SVG

Scalable Vector Graphics are very cool. I drew the house (really, more like the model) in Adobe Illustrator, exported to SVG format, and added some tags and stuff to make this cool "interactive" image -- click on each layer to make it levitate! There's a more complex animation in this About section, called "house animation.svg" which levitates each individual wall section when you click on it (gets sort of chaotic).

One of the things I like about SVG is it's open, so anyone can look at the source of the illustration/animation, read it (it's human readable XML), learn from it, reuse it -- just like HTML! Very cool.

You'll need Adobe's SVG plug-in, most likely.