stemkoski uses three.js to do crazy things. From Gamepad to LEAP Motion – everything seems to be possible in his big portfolio.
Check out interesting demos and examples at his website.
Also the LEAP Motion demo is very nice: http://stemkoski.github.io/Three.js/LeapMotion.html
“The goal of this collection is to provide a set of basic and instructive examples that introduce the various features in Three.js. The source code for each page contains detailed comments.”
Particle System – Path Movement
Particle System – Attributes
For more crazy stuff like GUI Controller, Webcam demos, particle Systems and much more – please check out: http://stemkoski.github.io/Three.js/#gamepad-test