How do i use the partion table in Ubuntu 10.10?

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http://askubuntu.com – I want to install Ubuntu 10.10 on my Macmini first gen(Snow Leopard),my iMac G3(Tiger), or my PowerBook G4(Tiger). But i still want my Mac OS X on it. I can't use the disk utility to partion my drives. Even though my macmini runs Snow Leopard the disk utillity says that I need 10 GB of free space even though i have way more then that. I tried using the Ubuntu 10.10 partion table to partion my computer(s) with it. But I can't figure out how to use it. Please Help!!! (HowTos)