Goodsearch

http://www.goodsearch.com/

I really like this one. I actually found it through the Warped Tour newsletter, but it allows you to donate the proceeds from the incidental advertizing on the search engine to a charity of your choice. They have quite a selection of charities, too. You can even change your charity for every search if you want to. It's essentially a yahoo search, so I have no concerns about quality. I think it's pretty cool. I've got it set up for the Open Hearth Foundation right now. They even had charities that I felt good about signing up for, so I'd definitely like to recommend this one.