This is Phun!

Wej

http://phun.cs.umu.se/wiki

Rick Stirling's post of the Crayon game reminded me of this. This is awsome, and you can really screw with physics. Kindof like the Crayon game, yet a lot more to it, as it isn't just a flash game.

Tumerboy

ya, it's pretty fun to play with, saw it a while ago. The liquid stuff is really interesting.