>>4
You clearly know jack about malware and the mechanisms they use to spread.
The vast majority of "viruses" find their way in through unpatched security holes in Windows or via email (or more accurately, via idiots opening every "LOLZ FUNNAY NEW SCREENSAVAR" and "W00T NAKED PICTUERS!" email attachment they receive). A lot of the time you don't even need to be doing anything to catch them, just be connected to the internet. Put an unpatched XP or 2000 machine on the internet without a firewall and you'll be infected inside of ten minutes without having to so much as start Internet Explorer.
On the other hand, if you're talking about the majority of all spyware/adware being caught by visiting websites, that is at least correct. But any browser, open source or otherwise, that doesn't use ActiveX (as IE does), is inherently less susceptible to such attacks because that is what the majority of spyware/adware exploits to install itself.
So the simple advice is, turn on automatic updates so any security holes are patched as soon as the fix is released, install a firewall (software or hardware-based, ideally both), and use a browser other than IE for web browsing. I've been running like that for years, and despite having no antivirus software I've never had a virus or spy/adware (I run occasional checks with housecall.trendmicro.com and Spybot S&D just to be sure).