Two interesting sites I stumbled across. One is goodtree.com, and the other is goodsearch.com. The concept is pretty simple; take 1/2 of the ad revenue generated from search ads, and donate it to charity. They use well-known search engines to power their site (like google and yahoo), so you get decent results.
The big difference between the two sites is that you can choose whichever charity you like at goodsearch (as long as it's registered in the US), but the charity must earn at least 20$ per year for the money to be sent (otherwise the money it earned will be given to other charities). This means if you choose a charity that is not well-known, it might not get the money. On goodtree, you have a list of charities you can choose from, and the money is guaranteed to go to the charity or charities you choose, but your options are limited.

So, most of the point of this post is just to be an plug for those sites, in the hopes that it'll result in more cash for charity, but there's some discussion fodder here too. Both of these websites are for-profit ventures; although I'm sure they had some altruistic motives for founding the sites, I'm also sure they're hoping to make money because the charity angle will draw people to their site. Also, there's questions to be raised about free donation sites period. I read an article online that said that rather than using free-donation sites (it was talking specificially about the hungersite.com), it's much more efficient to just donate an hour's wage. Thoughts?