I have been using Microsoft's Virtual PC on XP Pro (it doesn't run on XP Home) to facilitate various bits of beta testing of operating systems and applications. It is a real boon -- it allows multiple different operating systems(including non Microsoft operating systems) to be running simultaneously on the same box. It also allows multiple versions of a single operating system to be run at the same time making testing different application setups easy as well.
Anybody out there doing testing of various application betas or operating systems should have this product! The only negative seems to be that running multiple licensed products requires multiple licenses -- though I can't find a definitive statement on this from Microsoft (for non Microsoft products the licensing issues would need examining on a case by case basis).
