Anyways, here is a brief round-up of some cool examples of JS usage! May it serve as inspiration for anything you're working on now... for me, it is inspiration for visualization possibilities in the ed realm...
Impress.js uses HTML5, canvas, and JS to create prezi-style slides. AND it does so with 3D-like depth effects (Prezi can't do 3D).
Downside: It doesn't work on my iPhone; you will be directed to a more traditional view of the slides. It also doesn't work in early versions of IE (but that is no surprise). But if only...
Various 3D effects for web
Made possible, thanks to the WebGL API.
Check these out mainly for interests' sake...
WebGL Bookcase by Google Data Arts Team
Ctrl Paper by Romain Altain Aldea
Z-Type (a shooter game) by Dominic Szablewski
And in homage to Group Genius... look!
Multiplayer Piano by Brandon Lockaby
The Rational Keyboard (for any math nerds... or lovers of eerie sounds) by Fritz Obermeyer