Coriolis Systems' iPartition is a £29.95 ($44.95 US) utility that runs in Mac OS X and allows resizing of all of the relevant partition formats, including HFS+, FAT32, and NTFS. It provides a Mac-oriented user interface that may be easier to manage than some of the free utilities. As it is not capable of resizing the boot disk, it requires a bootable external disk or a boot DVD. (A tool to create a boot DVD is included.)