A bunch of Oliners put together a hackathon - we made a site called Back of the Plane (
http://www.backoftheplane.com) that helps users find interesting people on their flights.
It was a really interesting experience. For starters, I didn't know any Ruby on Rails 2 days ago (and how much I know right now is up for debate) so I got to learn it all as I went (pair programming turned out to be a great strategy for this). Spent a lot of time digging around in the various views, controllers, models, and helpers of our project, mostly debugging features that didn't quite work right and/or trying to extend already existing but limited features. On the other hand, every time I go to use it and encounter a feature I worked on, I get really excited ("Delete message? I made that!").