I tried to port taly_y's Marimo rendering (http://wonderfl.net/c/md93)
to Canvas. It works little slower in JS, but that's because I'm learning the language, not because JS is slow (I hope :)).
The basic idea of Marimo is simple. Get a 3D sphere, start slicing it with circles from back to front and on every slice draw hairs. To draw hairs we emit particles from a slicing circle and move it in random direction. Each particle leaves trail behind and the closer it comes to the tip of a hair the more transparent trail becomes.