In my neverending quest to help my clients save/make money, I came across GoodSearch.com. It's a search engine that charities can register on and then they make a percentage off of people using it. There is a related site called GoodShop.com that has store coupons and discounts.
So you just log in, choose your charity of choice, and then surf the web or shop online.
It's powered by Yahoo.
www.goodsearch.com
I told my non-profit client about it and they're thrilled!