My friend, Graham Mudd, works at Yahoo and has developed a really neat application that sits on top of Yahoo Search. Graham wrote about it on his blog here, but essentially it's a little Add In that recognizes when you search for a product and then gives you an option of clicking through a link to Amazon, or other large retailers. If you buy something through that link, a % of your transaction goes to Breast Cancer Foundations. Cool stuff with a social impact.
Nice work Graham.