UPDATE 1842 est 29 Jan 09: See this comment from Markofafreeman:
Installed it. Tried it out. Don't like it. Please take a look at this.
Bruce Schneier is renowned for his security expertise. The article is over two years old, but I'd have to see an updated article by him or someone equally respected in the field before I would trust TrackMeNot's effectiveness.
He mentions blackboxsearch.com as an alternative, but you basically have to trust blockboxsearch that they won't reveal your info. I need to read more about it, but it's possible that they don't even log it in the first place.
See also MOAF's comments here.
Overall point: the primary rule of COMSEC is they cannot hear/see what you do not say/do. User is responsible for his/her conduct.
Or "electronic countermeasures", to the acronym-challenged.
This product seems like a winner:
TrackMeNot is a lightweight browser extension that helps protect web searchers from surveillance and data-profiling by search engines. It does so not by means of concealment or encryption (i.e. covering one's tracks), but instead, paradoxically, by the opposite strategy: noise and obfuscation. With TrackMeNot, actual web searches, lost in a cloud of false leads, are essentially hidden in plain view. User-installed TrackMeNot works with the Firefox Browser and popular search engines (AOL, Yahoo!, Google, and MSN) and requires no 3rd-party servers or services.
H/T to TSLRF for the advice.