What & how do you code on your Mac?
jsvaughan: So - I code on stuff for my startup (http://www.bionicbooks.com) across all 3 of a g5 mac, an xp pc and ubuntu on a thinkpad.  I use java and the major downside of OSX is that you cant use the sun jdk, you have to wait for apple's version which is inevitably at least 1 major release behind (and generally forces you to pay up for the new OS release if you want it).  Additionally you have to deal with the odd keyboard arrangement and unconventional home and end key things which might be a hassle if you're not used to them.  Package management on the mac is more of a nuisance than ubuntu; installing mysql, php, whatever, is always much more of an effort (of all 3 machines the mac is the only one where i keep notes of how I installed things).I've seriously considered getting a Mac Air but for my stuff I couldn't live with OSX full time, I'd have to install Linux.  And if you're going to do that then you might want to look at other SSD laptops; rumor has it that Lenovo are going to launch an X400 based on Centrino 2 (Montevino) which came out this week.  Whether they do or not, the X300 is still an option.