Javascript is an elegant and expressiveprogramming language. If that surprises you, read this article about why javascript is so misunderstood. Once you get past the messy DOM and the browser incompatibilities (a library like jQuery will take care of that for you) there's a ton of fun to be had.
This is my stash of experiments in javascript intermingled with some useful code. At the moment it's all about using the "canvas" tag (notoriously unsupported in internet explorer) for animations and physics simulations.
Astroscout
My *ahem* "progressing" work on a javascript clone of the classic Asteroids game, based on the billiards algorithm below.
Billiards
A demo of colliding spheres.
Psychedelic flower
A demo of canvas animation with parametric drawing.