On top of that Linux is far cheaper than Windows (if even free), and it doesn't seem to get attacked by all the bad stuff out there like Windows always does. It's built for Internet security by default, XP SP2's firewall's too weak, and get really hacked into bigtime. Linux is almost like Fort Knox, and MS Windows is almost like, well, a country bank in the middle of the day, when anyone can just walk in and walk off with a drawer full of loot without warning.
Also, Mac OS X is half the price of XP Home, so there you go again. Unfortunately, the only catch is that you can only use it to upgrade an existing Mac, but some sneaky person can take advantage of that open sale on Mac OS X, and try overriding Win XP and using Mac's OS instead, but you have to mod the wazoo out of your BIOS in order to make it happen.
Also, Mac OS X is half the price of XP Home, so there you go again. Unfortunately, the only catch is that you can only use it to upgrade an existing Mac, but some sneaky person can take advantage of that open sale on Mac OS X, and try overriding Win XP and using Mac's OS instead, but you have to mod the wazoo out of your BIOS in order to make it happen.