If you wanted to try FreeBSD but didn't have the right hardware, or enough time to make it useful on the desktop,
VirtualBSD might fit the bill: it's a VMware appliance based on FreeBSD 7.1-RELEASE and features the Xfce 4 Desktop Environment and a few of the most common applications to make it very functional right out of the box. If you're curious you can have a look at the
screenshots, or proceed to the
download page and grab the
torrent file right away (note: VirtualBSD also works in VirtualBox 2.x as long as you create a new virtual machine and select the virtual disk from the archive instead of creating a new one).