Google has come right out and said that their staff decided which search results to return. They don't say how long this has been going on.
Atlas Shrugs, who has been omitted from Google results for awhile says: "Now that Hussein is in the White House, Google (a chief fundraiser and potential member of O's administration) wants to control the news on their man. I never saw this kind of news suppression under Bush. You could say anything, BushChimpHitler, and get away with it.
Entering the dark age ...."
Some other choices Yahoo AltaVista Dogpile