All the screens I could find of RGJ 1-5 submissions
Reddit Game Jam 06 starts March 25 and ends two days later (22:00 UTC).
Anybody can participate. Those who can't code should get together with coders in a team. Team size this time is unlimited.FOSS is encouraged, not required. [full rules]
From the subreddit's sidebar:
A game jam is an event during which all participants create games according to a provided theme within a short amount of time (usually between two days to a week). The Reddit Game Jam hosts game jams as part of the wonderful Reddit community.
Anybody can participate, experienced or newbie, flash developer or C hacker.
The main goal of this game jam is to be a learning experience for everyone involved. There is nothing to win except for fame, comments and of course karma."