A bunch of charity based search engines:

Everyclick which has currently raised over £350,000 for various charities. They have over 1,000 companies that use the engine as their preferred engine.
ClickNow has raised more than £100,000 since June 2005, and it's a partner to Ask.com.
MagicTaxi is another UK based search engine which has tabs to allow users to search Yahoo, Kelkoo and the Wikipedia. They give 50% of their income to charity, and each day a different charity features on the home page.
GoodSearch donates 50-percent of its revenue to the charities and schools designated by its users.
LetThemKnowItsChristmas is an engine that utilises Google and the funds go to the Christian charity World Vision.
CharityHome which donates 80% of its revenue to Charity. This one was started at the beginning of this month, so we've yet to see how much they make.
Search Kindly has so fair raised over $7,000 for various charities.
Charity Cafe is an engine that gives 100% of its profits to Greenpeace, WWF and Oxfam. It was launched in 2000.
Kazazz gives 10% of its revenues to various charities.
Clicks4Cancer gives 70% of its revenues to cancer charities.
The Carrot Clustering Engine takes results and clusters them, kinda like the name suggests. It searches the web using the eTools metasearch engine and then gives you a bunch of results.
Zvents - It's a search engine that looks for events taking place, such as performing arts, music, sport, art and crafts in various locations (I found events in the US, UK and Australia, though nothing in Berlin, so your milage may vary).
Onkosh Arabic information which styles itself as 'the only true Arabic search engine'. I have to admit, it's looking fairly comprehensive - web, image, blog, news search options, English or Arabic characters can be used.
Intelways used to be called CrossEngine, and before it was called that, it was called Mr.Sapo.