@minh - thanks

@littleguru, @mawcc - I really think you guys should consider using AV software. There's plenty that are good out there and you are putting yourself at risk by not doing it. I'd personally recommend AVG Antivirus software -
http://free.avg.com/. AVG has popped up at least once in the past six months with a warning on a page that was trying to execute malicious script running on a page. The site was a gamer site and was legitimate, but people were putting malicious script into ads that were then placed on sites. Other vulnerabilities that could already be on your machine are because of Flash. For example, a while back, if you went to one of the
12,000 sites infected with this Flash exploit, you could be infected. Littleguru's three steps above wouldn't have protected him from a Flash virus.