RAM

I finally discovered the real need for RAM. PoBo (my laptop) kept thrashing cuz it only had 256 MB of RAM. Got Brendan to get me an extra 512 MB for a total of 768 MB and now I'm good :). It never had enough RAM (Firefox and Thunderbird are hogs, Matlab is an elephant, OS X just naturally needs lots of RAM). Also upgraded my home computer to 768 MB.

Definitely with OS X, you need at least 512 MB of RAM, and the more the merrier - it actually uses extra RAM that you have.