Our friends over at Google have run tests, evaluating 66 million urls over the course of 10 months in 2007, to see whether or not these webpages hosted malicious code that might infect the average web-surfer. It's not surprising, at least to those of us at Symantec, that they found plenty. The chart over on their blog "shows the percentage of daily queries that contain at least one search result labeled as harmful. In the past few months, more than 1% of all search results contained at least one result that we believe to point to malicious content and the trend seems to be increasing."
Let's restate in regular person-ese: if you run a Google search, over 1% of your searches will include at least one site that is dangerous to click on! It's like a vicious e-game of Russian Roulette. Run enough searches, click enough links and you are bound to hit on a bad one. So what is a user to do? Use the safety features Google offers by enabling their SafeSearch in Preferences. (You visit Google.com in order to do this). Make sure your fellow computer users (spouse, kids, friends, etc) don't disable it! Then make sure you run a product like Norton Internet Security or Norton 360 with Browser Protection and keep it updated.