Linux live cds
new versions of linux are cool.. especially, the live cds which run from cd only (copy programs to RAM and run) and they wont touch hard drive. This is really cool for someone who wants to try linux and feel comfortable to install it.
Try kbuntu live cd at http://us.releases.ubuntu.com/releases/kubuntu/breezy/kubuntu-5.10-live-i386.iso
or try latest at http://cdimage.ubuntu.com/kubuntu/releases/dapper/flight-6/dapper-live-i386.iso
Other popular live cds include knoppix and suse live cd.
I think these live cds are good for windows users who want to try without having to install linux on their systems. Good luck!