VMWare offers a free product called VMWare Server, you can download it and run Linux on a virtual machene. In addition there is QEMU (http://fabrice.bellard.free.fr/qemu/) which is another free product that does the same thing. VMWare is easier to use. If you really wanted to give Linux a shot use this, not disk partitioning needed no dual booting.
I think Linuxlovers forget how daunting it seems to make the switch, though. Windows users are used to doing things a certain way on the desktop, and the simpler we make that first transition for them, the less likely they will be to say "Well, I tried it and I just never could figure out how to ......, so I gave up." That is why I like Linspire, Xandros (which I have only briefly used and never installed on my machine) and of course, Mepis. I have heard Mandriva is good for newbies, but never used it. Xandros and Mepis are KDE based, and SIMPLE to use. The interface is alot like they are used to and the support is really good. Linspire and Xandros, though, are not free. I dunno if Mandriva has a live cd...., which leaves, of course Mepis. I use Fedora on a file server (It "spans" a bunch of smaller scsi drives into one partition, which I could never get Mepis to do easily), but Mepis is my baby.
I have a VMwareplayer on an xp laptop, with the Ubuntu virtual machine, but I don't think a gnome desktop is a very good place to start for a newbie. JMO, but the collection of really nice widgets for games, faxing, scanning, email, websurfing, syncing palm pilot, printing, ftp downloading, disk burning, watching movies, etc in a KDE distro like Mepis is a slam dunk choice for a windows user looking around.
Heh. I feel like a skag dealer conspiring with another one "Let's just powder the candy we give em. We get em good and strung out and they will be hooked....."