the reasons macs are less of a security risk is because no one stores anything on them of consequence.
Well, I'm not sure what that's supposed to mean. I have a mac and I love it. The previous post is quite true: You can pay more for a mac upfront or you can pay for a PC for the rest of your life.
Mac are less prone to security issues because they simply don't have the market share that PCs do. However, staying under a hacker's radar is the worst security plan in the world. I know that if hackers ever decided to turn the full force of their efforts on the OS X platform, it would be pandemonium. At least Microsoft has a regimented timetable of releasing security updates. Mac users get it when we get it. BUT, having said that, when/if Apple decides to turn their full sights on security, you can bet it will put Microsoft to shame.
I'll second that about not using IE. It blows. Whatever browser you decide to use, make sure to download the NoScript plug-in.