OneBusAway.org W3C widget
Since I used to take the bus to and from work everyday, the OneBusAway.org real-time bus information was very useful to me. In Windows Mobile 6.5, Microsoft implemented the W3C widgets spec to allow developers to use web technology to create apps for the platform. There was an internal contest that went on before the feature was released, and I implemented a OneBusAway.org widget to provide easy and better UI to access the real-time bus information. I won the internal contest and got a free phone, but the biggest reward for me was that I was able to track where the bus is.
One of the very fun part of the project was the fact that I was actually able to work on the widget while I was taking public transit. Since it’s all just client side scripting, I was using my smartphone and a text editor on it to write parts of the widget.