I have need to run few Windows-only apps (games....), so I need to get in to dual-boot. I have a MBP with 160GB HD, and I have been thinking about giving Windows 50-60GB space on that HD. Prices of OEM-Windows seem to be more or less similar between XP and Windows. So the question remains: which one? I know XP and I know what it does and does not do. It has bulletproof compatibility when it comes to older games, and I think newer games will support it for a long time as well. But it's security is dismal and it looks pretty plain. Vista has better security (propably) and it look better. It will be supported for years to come, but I'm not sure about compatibility with older games. Also, it consumes more resources, and I'm especially concerned about HD-space.