TrackMeNot for Chrome
The TrackMeNot Chrome extension takes a novel tive approach to protecting your privacy from search engines that can create profiles of you based on terms you search for. Rather than hiding your searches from them in some way, it takes the exact opposite tack: It inundates search engines with a blizzard of background searches from you, so that no practical profile can be built because there are too many random searches. It generates those search terms from a group of RSS feeds from sites including the New York Times, CNN, and others.
It does this for the most popular search engines, including Google, Bing, AOL Search, Yahoo search, and Baidu (China's most popular search engine). If you're a Firefox user, you can avail yourself of the Firefox version of TrackMeNot, because the Chrome version of TrackMeNot works the same way. The searches are submitted in the background, so that you can continue using your browser as you would normally, with no effect on its speed.
TrackMeNot gives you a great deal of control over how you use it, including the search engines to which you want the searches sent, the number of searches done per hour, whether queries should be shown to you or remain visible, and so on.
All in all, TrackMeNot is a great, no-pain, no-cost tool for helping ensure personal profiles about you can't be built.
Note: This link takes you to this extension's page at Google, where you can automatically install the file into your Chrome browser.