I thought it might be useful to share what I've heard so far re: an application which will run under Windows 7 Professional 64-bit, and support Linux VMs. The rough consensus seems to be:
If you don't mind paying $170 (newegg price), use
VMware Workstation. This is probably a pretty good solution for me, since I need to learn virtualization, and VMware is the leader.
If you don't want the cost of running VMware Workstation, run VMware Player or Oracle VirtualBox.
If you go with VMware Player, load the optional VMware Tools for Linux.
If you go with Oracle (originally Sun Microsystems) VirtualBox, use the free, but not open-source version with good USB support.
CoLinux works, but not many people use it.
Nobody said anything about
Parallels Desktop for Windows & Linux. I emailed the company and found out 6.0 is in "short, private beta". You can probably get in on the beta test if you're interested. The guy at Parallels also said I'm looking for a "Type 2 hypervisor", which is an application that runs under a host OS, and supports VMs.
Windows Virtual PC does not support Linux well. I tried to use it, and it consistently dies without any error message when I try to load an Ubuntu 10.10 Desktop 32-bit CD. Supposedly it can be loaded if you run a text-based installer and change the graphics options, but life is too short.
There are other options, such as VMware Server, dual-booting, or booting from live media (CD or USB stick). I didn't list them because they didn't seem to meet my goal of a Type 2 hypervisor which will run under Windows 7 Professional 64-bit (i.e. my work laptop) and support Linux VMs.
Jerry J. Anderson