I've a MacBookPro and a MacMini at office. Have a look at this page where you can find some hints/experiences relative to the exploitation of this computer with Mac OS X. This other page tells you how to use Linux (ubuntu) on a partition of your Mac.

Since June 2011 I have a brand new Lenovo X220i. I use it with Linux (Ubuntu) although I've left a partition with the original Windows 7.

Here are the notes relative to my experience.

I bought an Acer Aspire One (SSD/Linux) version. Here you can find some hints/experiences relative to the usage of this computer.