Microsoft has released Virtual PC 2007 to the public, and has made it a free download. I havent' tried it yet, but people have told me it works very well, so if you happen to try it please leave your opinions.
From the Microsoft site:
"Use Microsoft Virtual PC 2007 to run multiple operating systems
at the same time on the same physical computer. Switch between virtual
machines with the click of a button. Use virtual machines to run legacy
applications, provide support, train users, and enhance quality
assurance.
Virtual PC lets you create separate virtual
machines on your Windows desktop, each of which virtualizes the
hardware of a complete physical computer. Use virtual machines to run
operating systems such as MS-DOS, Windows, and OS/2. You can run
multiple operating systems at once on a single physical computer and
switch between them as easily as switching applications—instantly, with
a mouse click." "
