VMware has a free new product called VMware Player. This allows you to 'play' precreated virtual machines on Windows or Linux. (You need VMware workstation to create virtual machines.) What's cool about this is that it should allow you to test drive Linux distro flavors in an easy and safe way. I think this method is preferable over a live CD since it loads faster and I don't have to reboot my machine. I can also see this as being useful for testing apps and OS's as you can just give someone the entire VM as a repro case. There are a few VMs up on their site already. I expect more to come.
For grins I tried out their 'browser applicance VM.' This is basically a stripped down version of Ubuntu Hoary. (Yes you just caught me running Linux again.) The performance was pretty snappy on my AMD64 box. I couldn't get the sound to work though. I installed real player to see how the video performance was - not great but better than I expected for running under VM. I don't have the root password though so I couldn't get it properly installed and working as a firefox plug in. - Anyhow, worth checking out. Both Novell and Redhat have VMs of their latest versions to try.