UPDATE SUNDAY 7:00 AM:
From NY Times: “Google’s Internet search service malfunctioned for nearly 55 minutes Saturday morning, upending users around the world with search results that carried false safety warnings and Web links that did not work.” http://www.nytimes.com/2009/02/01/technology/01google.html
All morning I’ve noticed that every search result from Google (but interestingly not the paid results) come up with a notice “This site may harm your computer.” Clicking on a link brings up this page:
I hope it’s something that Google fixes quickly. I had the same results using Firefox and Safari.