If you don’t want to shell off $70 for Partition Magic, read on.
I’m messing with my laptop trying to partition it for Kubuntu dual booting with Windows XP Home Edition. I’ve had one reformat already. And after I had some mistakes again in my partitioning procedure during Kubuntu installation, I am determined not to reformat the entire disk again. SystemRescueCD with QtParted (a Partition Magic clone) is my savior. I downloaded the entire 110mb iso, burned it to CD and booted with it. With QtParted, I was able to manage and resize the disk partitions ala Partition Magic, the Linux way.