We have spent a lot of time telling people how Windows Virtual PC and Virtual XP mode will allow them to run incompatible legacy applications on Windows 7. Unfortunately a number of people have come away with the impression that you can only do this with Virtual XP mode and that you can only run a single application at a time.
This is simply not true.
Using Windows Virtual PC you can access seamless applications from Windows XP, Windows Vista and Windows 7 virtual machines. You can have multiple applications running seamlessly in a single virtual machine, and you can have seamless applications running under different virtual machines at the same time.
If you look at this screenshot:
You can see that I have Internet Explorer and a command prompt running under the same (Windows XP) virtual machine. I then have Windows Live Photo Gallery running under a separate (Windows 7) virtual machine. All three of these applications have been launched directly from my start menu in Windows 7.