Hello everyone. I recently purchased a Macbook Pro, and felt that a definitive answer was in order for those of us with limited hard drive space in our Macbooks. Basically I use Windows to play a few games (right now) and my hard drive is packed full, and I do not wish to use anymore internal space for Windows. So, I'm installing games onto my Maxtor USB2.0 hard drive. I'll let everyone know how I make out. Currently: I have used Orbiter (http://www.orbitersim.com/) and I am very happy with the results. Framerate is a steady 60FPS, even using the Hi-Res Textures. Load time was extremely fast and I'm very impressed. Very fast zoom from 1m out to orbit, which is very demanding as well. Planning on: Half Life 2 Doom 3 Quake 4 Wolfenstein ET World of Warcraft Granted, I need to purchase the first three titles. But overall I'm hopeful that I will not see a performance hit using an external hard drive.