Ever wanted to paint realistic-looking brushstrokes in your browser? You're welcome.
An interesting look at what's possible with WebGL these days. The graphics aren't as detailed as they could be, but I suspect that's more to make it run smoothly on lower end hardware than a limitation of the technology. More information in the source link below.
This is a really awesome use of
<canvas>, Web Audio, and other web standards to create a globe that you can rotate to hear a mixture of radio stations from the coordinates you're looking at.