I just thought I'd let you all know that I've completed the installation of
Ubuntu Linux 8.04 (Hardy Heron) on a MacBook Core2Duo. And I'm impressed with how smooth and easy the installation was. Installation from the CD was just a few minutes and most things seem to work. Wireless didn't work right off, but with some simple command-line work that works fine, Sound works fine out of the box, as does display and graphics. The one problem I've come across so far, which doesn't work yet is right-click. But I'm sure I'll get that working too. Power management also works right away with sleep and hibernation. Will also have to work out how to get the function keys working.
So why put Linux on a MacBook? One answer is because you can. Another reason is to learn new things. The reasons are many. The Ubuntu people have done a great job with the latest version and it's easy enough for most users to be able to try it. I'm certainly not saying give up your Mac OS X - I am not! - but variety and choice are great things, don't you think?
Instructions for pretty much everything are
here.