Who doesn't like, that Linux makes a damage on your bootloader when you install Linux, you could use a LiveCD or you can install Linux in a program called "Virtual Box".
VirtualBox is a computer in the computer. You can appoint to Linux different hardware with this programm and then you can install Linux on a concluded virtual harddrive.
I've installed OpenSuse 11.1 on this VirtualBox and I'm very content.
For example I made the beta test of Windows 7 on the VirtualBox, because it makes it easier to test unsafe operating systems without that your normal system will get any damage.
So for all who haven't a partition for Linux or want to test Windows 7, download Virtual Box.