use one as a computer case for a PC?
Several years back, I sold a dual processor G5 I had laying around to a guy doing just that. He said he found himself in need of a Windows machine, but he couldn't bring himself to look at one in his home office. I think, at the time, there was even a program that made the Windows desktop look like a OSX desktop. I got fifty bucks for it on Craigslist.