Just saw this article over at The Register about the virus turning 25.
Elk Cloner, which spread between Apple II computers via infected floppy disks, has the dubious distinction of the first computer virus1 to spread in the wild. The malware is thought to be the work of Rich Skrenta, a 15-year-old high school student from Pittsburgh, who released it in July 1982.
So when ever a fan boy starts talking about how secure OS X is, you can remind the that it was Apple that had the first unsecured computer in the world.