Easiest way of previewing a Linux distro

[Bob Alexander <bob@ngi.it>]

Under XP I have used VirtualPC which I find very very very easy to use.

What is the best equivalent to do test installs of other Linux desktop 
oriented distros or even (shudder) Win operating systems ? The support 
for a graphic screen is a must of course and also some "virtual 
networking" enabling FTP/HTTP from the virtual machine.

VMWare is not an option for me.

I'd love to know about your real experience.

Thank you,
Bob