Once a week with usual firewall, etc. constantly active.

Question to the Mac users (as I'm thinking of getting one) is the Mac simply more secure or does it simply not get targeted (yet anyway) for malware, etc.?

Or is it a bit of both?

NEVER.
I'm a Mac.

@Reasonable: I think its a bit of both.

I have avast! on all 4 computers in my house, Ccleaner, and Spybot Search and Destroy. I barley ever run virus scans, but I'll use ccleaner and spybot every once in a while when i think about it. All of my computer run as well as they did with a fresh OS install.

'Sup, virus/adware-free Mac buddies!

*high fives and demeaning glares at the Windows users all around*

Never, I have an iMac.

A virus (or trojan, I'm not sure) spoiled my last Windows PC some years ago. That's one reason why I switched to Apple. The other reason is: In my opinion the Apple iMacs/Macbooks are excellently designed.

And CIV IV - the only current non-console game I play - is also available for Macs. Spore will be, as well.

i try to do it at least once a week.

once a week

The "gentlemen", who are programming viruses & trojans, are concentrating on the clear market leader Windows.

Never, I use Linux.

Because it's actually secure by design not by lack of users (unlike Mac OS X).

using a Macbook so there is no need :)