And as someone else pointed out, if someone can boot a CD disk on there, theres much worse things they can do to the machine anyway
Exactly. In fact, I'd go one step further. If someone can physically touch the machine, it's insecure. BIOS passwords can be cleared in 10 seconds. It takes almost that long to plug in a ribbon cable and hook a floppy drive or CD up, too.
Fact is, XP has a helluva lot worse security flaws in it than this. In a way, it's almost good, as it aids in recovering a damaged machine (or when dumbass users forget passwords) :-D