Resizing Partitions at Last!
As of 10.4.6, if you've got a GPT partitioned disk, you can use diskutil from the command line to resize volumes... nigelkersten@zombie: ~ $ diskutil resizeVolume Disk Utility Tool Usage: diskutil resizeVolume [Mount Point|Disk Identifier|Device Node] size <part1Format part1Name part1Size> <part2Format part2Name part2Size> ...