I’m a big fan of modifying your XP desktop to make it work better. The OSX route is one way to go. I prefer a complete shell replacement.
MAKE: Blog: Seven Steps to turn your PC into a Mac
“Instead of waiting for those Intel Macs to ship, you could just transform your XP PC in to a Mac, well- at least the look and feel. These are 7 steps to do just that. My pal Lenn did this awhile back, and people used to ask if his Sony laptop was some weird new Mac or something.”