Here are some HTML5 experiments and tools which are amazing. If you want to view the actual demos in HTML5 glory, use Google Chrome or Safari. If you’re not yet using a HTML5 enabled browser, I’ve added videos which show you the demo of those sites as well. Link:

HTML5 Audio and Canvas Experiments

Link: http://9elements.com/io/projects/html5/canvas/

Can’t say much – other than Awesome! Move your mouse around and click around to get tweets on HTML5.

Harmony Drawing Tool

Link: http://mrdoob.com/projects/harmony/
An online sketcher which uses HTML5 and canvas to provide a procedural drawing tool. Works great and people with artistic tendencies can do quite a bit with this.

Audio Visualization using HTML5

http://www.storiesinflight.com/jsfft/visualizer/
This demo visualized an audio track using the HTML5 canvas tag and uses the audio tag to play the music. You’ve got to view the actual HTML5 demo of this.

JaVortex

Link: http://url3.tk/?p=nbody
A Gravitational Attraction Particle Engine n-body simulator in Javascript and uses HTML5 canvas.

3D Model Viewer

Link: http://www.giuseppesicari.it/progetti/javascript-3d-model-viewer/

A 3D model Viewer using Javascript and HTML5. The demo lets you interact and turn around the model in 3D space.

If you know of any other cool HTML5 demos, let me know by commenting below.