Making sense of Fitts' Law

Particle Tree has an excellent article on Fitts’ Law. That’s the one that, amongst other thing, leads to putting the Dock and Start Menu buttons on the edges of the screen. You definitely want to check it out, if only for the terrific images used as demonstration, like this one:

ParticleTreeFittsLaw.jpg

Of course, if you’re more about the math[1] you could just read up on ye olde’ Wikipedia.

fn1. There’s math in UI design?