I bought Neato's
discLabel program - it's pretty cool. I had it for PC and when I switched, I just had to get it for the MAC as well. The only drawback is that you have to use their labels - well, I haven't figured out how to use any others.
Also, if you go to Wal-Mart and pickup a pack of Memorex Labels, they are cheaper than Neato's (Fellowes) and they come with ExpressIT
for PC and Mac. Memorex labels also seem to be ubiquitous. ExpressIt is like a lite version, I think there's a full blown one that you can buy, but I haven't needed it - ExpressIt works good for me. They also give you a template for PhotoShop which is kinda handy as well.