I'm about half way throught this weekend's Ludum Dare 21 (althought the traffic level is really bad right now.) The theme is Escape.
Tools so far:
My Pac Man mechanic isn't exactly fun, but it too late in the contest now to change :( I'm using momentum or forces to move the player, which at least one interesting difference over the classic game. This make moving around a little less straight forward, and might have some emergent strategies, we'll see.
Interesting! Notch of Minecraft fame is video streaming live as he programs his Ludum Dare 21 entry!!