I found a very nice ISO that installs on a USB Drive or CD-R that will allow you to do the Parted functions without having your harddrive mounted (which is a requirement for manipulating the partitions.) It is at
http://partedmagic.com/ and I personally downloaded it from sourceforce.net with wget. If you boot with the USB or CD-R you can manipulate your partition. For instance, on my old machine, I had one gigantic partition with Windows XP on it. I shrunk that down by 300 gig and installed Fedora 17 on it.
- Raj