There's also DuckDuckGo.com. Despite the name, it's actually quite decent, and the "related" non-boolean search lands on top.
The difference is, DuckDuckGo is headquartered in Paoli, Pennsylvania. You have to dig through their site a while to find that; try the Hiring section. That means they are subject to US fed/state data retention laws and government requests.
Ixquick is headquartered in The Netherlands and (understandably) boasts about not having provided one byte of data to the US government. They've won EU awards because those governments actually recognize the value of privacy. Please see this page for a reference.
Don't get me wrong, DuckDuckGo sounds good. Sounds like they certainly don't actively track you. But I don't see them bragging that they "keep no data to hand over in the first place" and I would be truly surprised if that is entirely an option for them. Certainly they can't tell the US government to piss up a flagpole if and when fishing expeditions come in.