I prefer Ubuntu 10.10 because it's more useful than 12+ versions. Furthermore, Ubuntu gets installed on a Mac mini G4 more easily than other PPC Linux distributions such as Debian.

I noticed that both FreeBSD and Ubuntu PPC uses the almost the same size (~1MB) newworld block to boot from PowerPC and it's very easy to create and integrate this newworld boot block during installation (of Ubuntu or FreeBSD) But it's a bit tricky doing that in MorphOS

My ultimate aim is to install those 4 OSes: FreeBSD, Ubuntu, Mac OS X and MorphOS. So far I have managed to install 3 of them on one harddsk and they are selectable from Apple alt-boot menu. Now I'm trying to add MorphOS to the harddisk.

Mac OS X's Disk Utility turns out to be quite useful in adding and resizing partitions at the end of the harddisk. I also noticed that GParted in Ubuntu PPC doesn't work on the harddisk on which I installed 3 OS'es. It doesn't work on Ubuntu Live CD either, it might have something to do with having too many partitions on the harddisk.