Hmm... I may not be so anti-address book after reading this. Once you know you have a virus sending itself to your list, you can notify them immediately to stop it from spreading. Never thought of that - thanks, Larry!
Hint: For your mailbox options, make sure there's a column that shows you the size of the email. A normal email with no attachments should be no larger than 3 or 4 K. If you see something that you don't recognize that is around 100K with no attachment, it is most likely a virus.