Mozilla Firefox 4 contains a new audio data API which enables reading and writing of raw audio data. This demo uses DSP.js to read audio data from a sample ogg file and displays the output as a spectrum analyser.
See demoiOS 4.2+ contains a new API to read accelerometer and orientation information from the mobile device. Here's a quick demo of it running.
See demoThought I'd get my hands mucky with Box2DWeb - a JavaScript port of the Box2D library.
See demoA simple app to convert colours between hexadecimal, RGB and CMYK formats.
See demoA simple demo to use the geolocation APIs to display your current position on a google map.
See demo