Re: Mac won't boot ubuntu installation disk
You could try precise (ubuntu 12.04). I found that the standard 12.04 installer disk booted fine and installed on my iMac (mid 2010) whereas the standard 11.10 disk didn't even boot.
For 11.10 I had to download the special amd build for mac before I could get it to boot off the install disk.
12.04 is behaving very well, despite being a beta. However I prefer using archlinux (kde desktop) in a virtualbox guest image hosted on OSX. It gives great flexibility and no detectable loss of performance.
Windows is cheap, but linux is free