GUEST, and the other knee-jerkers:
If you're that worried about getting hit, why stop at replacing outlook- replace your entire operating system. Mac's have far fewer viruses, and Linux has even less again.
Don - the more people out there who have your email in their address book, the more times the worm will try to send itself on to you. Don't think of it as "they're all out to get me" - instead consider it a measure of your popularity!