Reply #14: just did on two different intel macs ...

[guyton]

on both, used disk utility to shrink the existing partition and make a big play area at the end of the disk.

booted ubuntu and told it to grab the free space at the end of the disk.

worked pretty well. only two problems ... on the laptop, the trackpad didn't work very well, but
both a normal and bluetooth mouse worked fine. And on the tower (with a two-connector video
card), I had to move the connection to the other port to see the screen.

Was only testing, so I didn't play with EFI hacks, just using the system picker (hold down option)
was enough to pick the os-x vs. unix boot (which showed up as windows to the picker).