It's always fun to have smart people hack away at old phones, sometimes cool things can happen. Case in point: the folks at xda-developers have gotten Android 2.1 (yeah, that's 2.1) onto 4 old Windows Mobile phones. The HTC Kaiser (aka AT&T Tilt), Vogue, Niki, and Polaris have all been hacked to run the elusive Android 2.1. This is especially amazing since so many real Android phones have yet to be updated to 2.1. Seriously, if a Windows Mobile HTC Kaiser can do it, can't Motorola get the Droid on 2.1 already?
There are, of course, kinks to be worked out--the camera doesn't work, bluetooth is wonky--but from the sounds of it, everything else is just dandy. If you happen to have those old WinMo phones laying around, it could be a fun weekend experiment. And it should go without saying, but you kind of have to know what you're doing.