Something fun (and educational!)

SodaPlay is basically a physics-based simulation that allows the user to design a form and see how it would function with varying amounts of springiness, gravity, friction, etc. Perhaps the coolest thing about it, however, is that it is sort of like SketchUp and Google in the sense that you can play with other people's designs as well. Not entirely technology and art, but the implications are interesting! And it's fun to play with.