Many of my friends who have recently gotten the new Intel-based Macs and they've been going ga-ga over Parallel's virtualization software that lets them run WinXP inside of OSX. I don't have a Mac-Intel, but I would like to be able to do this on Linux. It looks like there are a few choices, but I ran into this article about installing QEMU which is a emulation software that the review claims runs pretty fast. Another option that seems to be Xen which is a virtualization software for x86.
A few things still bothers me about my current linux desktop is that the video drivers/software still aren't as good as their windows counterpart. It seems that I can still do more with the windows set of drivers from Nvidia then the linux drivers. I'm sure there are some manual tweaks that I can do directly to the configuration but I haven't had as much time. This basically means that I can run WinXP on Linux, but the visual look isn't as nice as it looks on being on Windows natively.