Instead of going to www.google.com for your searches, use this url: https://ssl.scroogle.org/
Scroogle is an anonymous proxy to the live google, but it doesn't identify you (your IP address which is the online equivalent of you) with any of your search terms. The added bonus is that your queries are encrypted via SSL just like a credit card transaction with an online business so your ISP or your employer if you're searching from work, cannot log your searches either. Also, there are no google ads in the hit lists.
For more reasons why scroogle is a good thing see, this wikipedia article.
If you use firefox's searchbar for your search, you can easily add scroogle to it by visiting this page, and by clicking "Scroogle SSL English" (it's the 23rd one in the alphabetical list).
