When my corprate office handed me a laptop with a 40 Gig drive that was one big NTFS formated partition, I used a Knoppix (Linux Live CD ver 3.3), to boot into a linux enviorment and I used the Qtparted tool that is standard in that distribution. It worked like a charm for me.
Qtparted's website is:
http://qtparted.sourceforge.net/
Knoppix information (for those of us stuck on using english):
http://www.knoppix.net/
