On the other hand. Back in college, my (then-acquaintance, now-roommate) friend Matt was running Linux on a PowerBook, and seeing his success got me into the whole Linux/PowerBook scene (which I loved, but eventually the laptop got too beat up and is now retired). Then he became a Mac zealot for a few years, even getting his friends to switch.
Recently, though, he switched back to Windows, primarily because Firefox on Linux is so agonizingly slow. (We have the same hardware, and you can honestly feel the difference between his Firefox/Windows and my Firefox/Linux.) He not only uses Outlook now (thankfully not for email), but I've even caught him using IE once.
There's a lot of pointing and laughing on my part, especially whenever it blue-screens or locks in other ways, but I know he's aware of his options and has apparently decided that buggy+crashy+fast is the balance appropriate for him. Needless to say, if we ever get a wired network I'll have to adjust my firewalling because I can't trust any network his computer is on...
