The global game jam was on the weekend, and I spent the days there making a game Zeppelin Escape.
There isn't much time in 48 hours, and we were learning Unity, and trying to avoid the beta bugs, so it was an interesting experience. We couldn't figure out how to get Unity's collision code going so I wrote it again from scratch, as well as doing the "AI" for the enemies, movement system, and 'designing' level 2 & 3.
There were about 25 people there and all round a great time was had. Highly recommended.