Bootable Ubuntu on a Macbook Pro with VirtualBox
Last year I managed to get Ubuntu 10.10 running on my 13” Macbook Pro so that I could boot into it natively, AND have it accessible as a virtual machine via Virtualbox. When I did that, I wrote a guide. It has been hanging around on my desktop for too long, so I am just going to paste it here, and be done with it.
These instructions are slightly out of date, but they should work, more or less.