Surely you may still get sent an email with a virus attached that you could then forward on to friends with PC's.
http://antivirus.about.com/od/macintoshresource/tp/macvirusfaqs.htm
Andi.
ive seen 1 mac virus, 1, it played around with the settings of the guys macbook, luckily he had nothing on his mac so we just told him to wipe it, so it was clean
What was it?