Biases and Restrictions in Google Search:There's lots more. It's definitely worth studying this and keeping a link to the reference.
...5. If you don't like Google's personalized results you can log out from your Google account, disable the Web History service or turn off the personalization bias by adding &pws=0 to Google's URL. Note that the parameter is not persistent and it only works for the current search.
6. To restrict your search to the high-quality (?) web sites included in the Open Directory Project, you can append &cat=gwd/Top to Google's URL or perform your search at Google Directory...
I tried the &pws=0 parameter when searching for my own stuff, and it was neat to see the search results change. It wasn't a large change, but in general my stuff moved down the main page one step.