What Virus Scanner?

After taking a week long vacation and wrestling with a naughty internet connection, I'm back. I finally got along to installing Linux to my hardrive (I couldn't in the past because my network card wasn't supported, but now the router's in my room) and when my Dad first saw it in all of it's KDE goodness, the first words out of his mouth were (somewhat shortened) "Where's McAfee?" I tried to explain to him that it's Linux, and you don't need a virus scanner on Linux just so much as you don't need one on a Mac. Apparently, in his world, you also need a virus scanner on a Mac. If someone has an actual need for a Virus Scanner under Linux or Mac, short of someone else making them, let me know in the comments.