Jackson Pollock.org was spelled incorrectly, thereby giving a dead link and none of the hours of fun for those who click. I love me an interactive site to get my creative juices flowing. Click and make your own Pollock painting. (I can do this for hours.)
Another favorite interactive site recommended by my sister-in-law years ago: Superbad--hours of another kind of weirdness. You never know what each click of your mouse will do, but the graphics and content are always something interesting.