Mac Drive Partitioning
I had a recent need to partition a disk without destroying the data, and basically the hunt took the best part of a week.

The omissions and failings of Apple’s Disk Utility have caused a whole set of tools to appear - the most famous of which is DiskWarrior. Even in Leopard you can only do so much with the partitons unless you’re willing to go back to scratch and wipe one or more of the partitions.

The upshot is that here are two ways to do it, the easy expensive way and the difficult cheap way.
The easy expensive way, which is what I ended up doing was to buy
iPartition which is a good product but cost approx £30, which probably equates to about $50.
This is an excellent way to do it if you’ve got the cash, the re-partitioning took a couple of hours but the interface is straightforward and it also re-partitions bootcamp partitions which is big advantage.

The hard ways to go it are basically use
gparted or the line command. I had no luck with either. There is also Volumeworks which I didn’t look into.
Gparted is a Linux tool and you can reboot your machine using it once you’ve burned it. Unfortunately it doesn’t grow HFS/ HFS+ volumes (or at least I couldn’t get it to do that), so you would have to use it in addition with Apple’s disk utility.

line command method looked more promising but again I got so far and it just stopped - I got error messages that the file ssytem wasn’t recognised - given that it was created using the Disk utility this seemed a bit rich.

If you want to repartition a Windows
bootcamp partition for free without losing data, you’ve really got some fun ahead.
iPartition does this in one step.

Honestly, I’d just buy iPartition, life’s too short!