Kevin-- Don't get me wrong, Apple makes a pretty good product, and I'm not dissing it or anyone that chooses it... I just caution anyone that believes the 'message' without questioning it, no matter who delivers it, Apple, Microsoft, Google, etc. Believing that a software product is invulnerable leads to letting our guard down, which bites us in the ass eventually. The Internet is a cool place, but there are lots of bad guys itching to pull a fast one, and good guys with bad judgment, so keep your wits about you.
There are other kinds of malware besides viruses, currently trojans and other information stealers are all the rage, the sneaky ones operate flawlessly so you don't even notice that they are running. All current (and past as far as I know) operating systems are vulnerable to these threats. Some are patched, but the worst ones are the ones we don't even know about yet, called zero day exploits.