Starting my new job at Ubuntu was a lot of fun. It also gave me the opportunity to buy what I think is one excellent piece of hardware, a MacBook Pro 15".
Setting it up was quite fun as I started with the development version of Gutsy. Now that it is in beta, everything works well if you follow the instruction at https://wiki.ubuntu.com/…ro/SantaRosa. I've updated the instructions a bit as I went along and wrote a little daemon script to help me have a cooler laptop. You'll be able to find it there, and more precisely at https://wiki.ubuntu.com/…saFanControl
Have fun with your Ubuntu on a Mac :)