I guess it's up to the individual, but I wouldn't be comfortable not having virus/spyware protection on my computer, and that includes Macs. Yes, viruses on Macs are a lot more rare than on PCs, but they can and do happen. In fact, one of my friends got a virus on her Mac about 6 months ago. Not saying that's common by any means, but it just illustrates that no OS is infallible, including Macs.