Folks, this holiday season I am giving you the gift of Carpal Tunnel Syndrome. Because you're going to click on this link to Inspirograph, which is a browser-based spirograph emulator developed by engineer Nathan Friend. And you're not going to be able to stop playing with it.
You choose how many teeth you'd like on each gear; you select which gear you'd like to be fixed and which rotates; you choose the ink color and which hole to plug it into; and the darn thing is even sort of pressure-sensitive, meaning when you go over a curve twice it gets darker.
If your boss walks in on you, explain that you're working out some logo concepts for a new client.
Friend, by the way, is currently working on a mobile version.