I think mandrake installation CD uses diskdruid for partitioning. I could't find a site from where the software could downloaded. You can pop in the installation CD, do your partitioning and reboot without installing but that's is a dangerous operation (one mistake and you could mess up your system). One has to very care ful here.
OR
Try FIPS:
http://www.igd.fhg.de/~aschaefe/fips/
I've heard that it has issues incase of dual book with xp. But it's suppoed to be quite stable otherwise.
Don't forget to provide your feedback so that other can benefit too.
HTH.