My new tumblr. Trying to figure out how to use it and integrate it with the crapload of other lifestreaming services I use.

TempNum - A Twilio Project

As many of you who follow me on Facebook or Twitter know, I recently launched TempNum, a (currently) free service that gives you a temporary phone number for three days to use for both inbound and outbound calls.

If you haven’t yet seen it, check it out (go ahead and sign up!) and let me know what you think.

Now that the service is launched, I thought I’d share a variety of thoughts about the project.

How Does It Work?

TempNum is incredibly simple to use. A user simply enters registers with a current telephone number that they use. They are then assigned a TempNum - a real US 10-digit phone number that is theirs to use for a period of three days.

A user answers an inbound call by simply picking up the phone. Calls to the user’s TempNum are forwarded to the user’s real phone without any action or awareness from the calling party.

A user places an outbound call by calling their own TempNum from their real phone. They are asked for the outbound number, and the call is connected with the TempNum as the caller ID.

It’s that easy.

Why Did I Make This?

A variety of different factors all came together at once, leading me to build this service.

Desire…I wanted to build something. I’m not a full-blown developer, but I do have some coding experience from various personal/professional projects and have always loved the satisfaction of building something. Bonus for functional and useful. I didn’t get to do too much of that while in business school (my work skewed more toward spreadsheets, regressions, and other quanty/analytical stuff), so I was eager to get my hands dirty on something.

Interest…In line with the above, I had some criteria about what I wanted to work on. I didn’t want yet another HTML/PHP/MySQL exercise. Yes, I wanted to utilize and re-familiarize myself with those tools, but I wanted to add on a layer of something entirely new. Luckily, I had become familiar with Twilio, a provider of cloud communications/telephony services. I’ve been a big fan of what their technology enables developers to do and was really interested in learning their API, understanding in detail how to use it, and incorporating it into my project.

Context…Finally, my recent move to California gave me some context for the project. My move provided me a more complex set of phone needs. On the one hand, I wanted a ‘local’ number without losing my current number or adding new lines of service. Google Voice was fine for that. On the other hand, I was using craigslist a lot for housing and furniture shopping, and wasn’t fully comfortable giving out either of my permanent numbers.

Thus - TempNum was born out of an interest in building something, a cool new API that I wanted to use, and a relevant problem around phone numbers that I wanted to try to address.

Under the Hood - Technical

HTML and PHP drive the basic functionality of the website. A MySQL database is used behind the scenes to manage user info, registration periods, and assignment of TempNums to users.

The Twilio REST API is the powerhouse for pretty much everything the service “does”, from provisioning phone numbers to initiating inbound and outbound calls.

What I loved most about the API was that I could use PHP - a language I am familiar with - to interact with it. That meant I was spending more time learning what I could do with the actual API, and less time learning the details of TwiML (their markup language which I admit is really concise and simple to use) or the basics of an entirely different web programming language.

Under the Hood - Functional

The basic call forwarding functionality of the service is described above. The original idea was to set up a simple service that was essentially a front end for Twilio for use by the average user. That is - the service would do nothing more than provision a number, set up forwarding and allow inbound and outbound calls, and a few days later shut everything off. These are pretty simple things to do for anyone with a Twilio account and OpenVBX, but I wanted to make something requiring as little effort from the average non-technical user as possible.

As I began to build the basic functionality, I started realizing the very real costs of running this service, the largest of which seemed to be the cost of acquiring phone numbers. At $1/month each (plus usage fees), it didn’t make much sense to buy a number, use it for only three days, and release it. Instead, I could use a number multiple times and lower my average cost of servicing a user. Thus, I decided to build a dynamic inventory of numbers for TempNum. Numbers could have one of four states:

Available - Acquired from Twilio. This number is sourced and ready to be assigned to a user. If numbers aren’t available at the time of a user registration, a new one is grabbed from Twilio.

  Assigned - This number has been assigned as a TempNum to a user and is actively in use.

Unavailable - This number was once assigned but has passed the expiration. It is currently in a waiting period before it will be reassigned. The waiting period is designed to eliminate potential wrong numbers/user confusion in between assignments. After the waiting period, the number becomes available again.

Inactive - This number is no longer owned from Twilio and can no longer be used. I release all unassigned numbers (Available or Unavailable states above) at the end of the month. This lets me get rid of ‘unused’ numbers before Twilio bills me for the next month.

Basically, numbers go through the following cycle:

Available —> Assigned —> Unavailable —> Available —> Assigned…  [repeat]… —> Inactive

Ultimately, I am able to recycle numbers to maximize their usage, and expand and contract my inventory to minimize unnecessary costs of number ownership.

What’s Next?

My original intent for this project was to exercise my basic dev skills and learn a new company’s API. But simply going through the process of building this got my head spinning about what to tackle next - both from a business and a technical perspective.

I’m not quite sure whether this is something I’ll devote all my time to or launch as a full-scale business, but here are some things I’d like to do next:

- Get qualitative feedback from users about likes, dislikes, feature wish-lists, etc.

- Understand usage, both by talking to the users and by analyzing the data from Twilio and my own database. Perhaps automate some analytics/reporting

- Implement some sort of SMS functionality. TempNum is currently voice-only

- Explore different pricing models. I’m currently supporting three day terms of service out of my own pocket. But there are a definitely a variety of pricing models I could explore should this take off, i.e. premium pricing for longer registration lengths, tiered usage, etc.

What do you think?

Whether you’re a developer, user, or casual observer, I’d love it if you checked out TempNum and told me what you think. Drop me a note: support at tempnum dot com


Thoughts on iPad

A friend of mine spent some time in the Apple store, played with the iPad, became hooked, and then emailed me asking for my thoughts to help him decide whether to pull the trigger. I’ve been meaning to to publicly post my thoughts on the device so I figured sharing my reply would be a good start.

This email really only addresses why I chose the model I did and some general thoughts on usage, and omits some more specific thoughts I have on individual features/aspects of the product. I’ll try to post some more of my perspective at a later date.


"I went with the 32gb (mid) Wi-Fi only model- the one you’re looking at. I too didn’t see a need for data everywhere that justified the extra $130 price diff plus $30/month service fee. Most of my usage has been at home or at school so this has worked fine.

I’ve found that I mostly use it for web/apps/games and not as much for other media. Most of the video I’ve watched so far has been streaming (via Netflix or ABC apps). So therefore I haven’t really been constrained by the space. I did load a few movies on it with file sizes between 600mb and 1gb, so there’s definitely sufficient room there (note: these were bootlegs of questionable quality, so perhaps ‘legit’ movies are larger). Finally, I already have an iPod/iPhone so while I loaded some music on there just to see how it was, I don’t use it for music listening at all.

I think the most interesting thing has been how much it has changed how I use my phone and computer. I really only use my phone now for tweeting while in the bathroom or in the car, and I only use my macbook when I’m doing heavy-duty work. Everything else in the middle – reading/writing emails, surfing, facebooking, gaming, etc – is now done on the iPad.

I think its a phenomenal device and you should definitely get one. Yes – like the iPhone there will likely be updates every year that improve on the specs and features, but I say you just go ahead and get it now :)”

Brenton Duvall

—Ambien (Sleepy Trip)


Ambien - Little Wayne/Passion Pit mixture

i like calling these mixtures. my daughter’s friend calls them that.

This is dope. Loving hip hop mashups with indie/electronica.

LCD Soundsystem

—Dance Yrself Clean

Same here! I’ve already listened to it (the whole album) twice today. Going on #3 now.


LCD Soundsystem - Dance Yrself Clean

I am loving the new LCDS album.


LCD Soundsystem - Dance Yrself Clean

This new single goes from great to amazing just after the 3 minute mark. Whoa, I love this.

I am utterly fascinated by modern windmills.

Yes there are limitations on how well they work, like the fact that wind is weakest during the day making these ineffective when electricity is demanded most.

But nonetheless, I love that these things exist. Seeing one makes me happy. Seeing hundreds scattered across farmland on a sunny day is just downright beautiful.

(taken somewhere in Indiana)

[Update: Ten minutes after posting this I checked Twitter and realized it was Earth Day, making this posting from the back of a Civic Hybrid the most accidentally apropros thing I have ever done.]

I am utterly fascinated by modern windmills.

Yes there are limitations on how well they work, like the fact that wind is weakest during the day making these ineffective when electricity is demanded most.

But nonetheless, I love that these things exist. Seeing one makes me happy. Seeing hundreds scattered across farmland on a sunny day is just downright beautiful.

(taken somewhere in Indiana)

[Update: Ten minutes after posting this I checked Twitter and realized it was Earth Day, making this posting from the back of a Civic Hybrid the most accidentally apropros thing I have ever done.]

SXSW: A Review In T-Shirts

Just got done with some laundry and realized that one of the lasting benefits of going to SXSW Interactive this year is all of the free t-shirts I came home with. All told, I probably came home with a dozen new shirts, most of which I actually wear (a couple were off-sized, including one women’s size…woops).

My shirts came in a variety of colors and designs, some fantastic, some less so. Without further ado, my review of SXSW t-shirts.


Credit for my least favorite shirt goes to the hot mess that is Hot Potato. Like many others in this set, they went with a solid quality American Apparel tee, but in the least appealing color ever: an odd, earthy, sandy, tanny brown that just looks weird. Throw in a logo that looks like zombie hot dogs and you’ve got a shirt I’m not keen on wearing out of the house.

Also - I don’t really know what Hot Potato is. It seems like a check-in/location-based service more around experiences than physical locations, but I haven’t had the desire to try another one of those services out.

Sure I’ll Take One

Simple and inexpensive, this WePay t-shirt isn’t trying to be anything special. Its no American Apparel, but the simple color and logo scheme make it great for wearing out of the house and not looking like a geek. Added bonus: the CEO is also responsible for this piece of magic (which I have, in fact, ordered and am expecting any day now).

WePay is an awesome service focused on group collection/management of money (think student clubs, travel groups, etc). Hope to see these guys take off!

Sure I’ll Take One - 2

Got this one at a Facebook event targeted for app/game developers. Though it looks blue, it’s actually a nice American Apparel charcoal (I love charcoal). This shirt screams geek, but it gets bonus points for aesthetics and its Austin callout, which is funny only because the actual location-based services seemed to miss that opportunity.

Second Place

This isn’t really my second favorite shirt, but rather the shirt of the second place winner of SXSW. Location wars were the big theme at Interactive this year, with Foursquare and Gowalla being the two main services battling it out. Unfortunately for Gowalla, Foursquare won (for me at least).

That said, this shirt is not terrible. The green is a bit much, but the logo and branding aren’t obnoxious. My guess is most ‘normals’ don’t even know about this service (yet) so the shirt will be more of a mystery than a badge of nerdery.

Very Punny

Dailybooth locks up the award for punniest shirt. Great white on black execution for a photo-based service. (Though I’m not sure if I’m keen on taking a daily webcam pic of myself.)

They also had versions of the shirts  that said “we put the pic in epic”, though I wasn’t able to snag one in my size.

Awesome Potential, Awesome T-Shirt Demonstration of that Potential

Stickybits is a service that lets you tag and attach digital content to real world objects using the simple and established standard of bar codes. I think this is an amazing opportunity to attach a cool layer of digital data to the physical stuff that’s already around us in every part of our life. Use their free app to scan barcodes and see what people are tagging/attaching.

While the white-on-red tshirt is beautiful on its own, I love how they implemented their service on it, attaching a bar code to the back that you can tag & scan. I’m not sure if they created unique bar codes for every shirt (that seems like a logistical nightmare), but I was the first to tag the one on mine. Their service bridges digital and physical, and their marketing does the same. LOVE IT.

The Conversation Starter(s)

Some would say I’m obligated to love this shirt (Bump's founders include two friends and ex-classmates from bschool). And that's somewhat true. But I love these shirts not because of my connection to the company, love for the service, or because THEY GAVE ME TWO (!), but because of the conversations they start.

Every time I wear this shirt, people approach and talk to me about the app. At SXSW, people thought I was a part of the company, and talked to me at length even when they found out I wasn’t (it helped that I said I knew the founders). But the effect is global. I was recently in Cabo San Lucas for spring break, and wore my Bump shirt out the day we went scuba-diving. Within seconds of seeing me, my divemaster commented that she had the app installed on her iPhone and loves using it. She was about to take me on a potentially dangerous trip underwater and wanted to instead talk about Bump, instead of, you know, asking for my name.

So Hip

I just love Brizzly’s shirt. American Apparel, charcoal, interesting logo, no branding. This is a shirt I can rock out anywhere. It’s got enough color and design to stand out, but not so much that it seems obnoxious or awkward. I haven’t quite figured out if the service - basically a social web aggregator - has much value to me yet. But the shirt? Abso-fucking-lutely.

First Place

Like its win in the location wars (to me, at least), foursquare won in the t-shirt wars as well. I’ve become a huge fan of the service and don’t feel nerdy when I wear it. I love the pale yellow color (perfect for spring!), incorporation of badges into the design, and the heart shape, which makes it seem sort of cool and hipster-y (or at least that’s what I tell myself).

The coolest thing about this shirt, though, is that unlike the others I had to actually earn this one. The foursquare team set up a real-life foursquare game outside the convention center that people were lined up to play. The only way to get a t-shirt was if you won your way into the “Mayor” square. It took me a few tries but I eventually got one!