I recently helped co-organize Jerusalem Twestival ’09 which raised money for Charity: Water, an organization that provides villages in Africa with clean water. The Jerusalem event was one of over 180 “twestivals” on the same day worldwide and featured booths with different clean technology and water technology companies and organizations along with musical performances.
One of the organizations at the festival was Green Any Site (GAS). Green Any Site takes advantage of affiliate sales programs, such as the one offered by Amazon.com, by offering a “Green This” bookmarklet that people can add to their browser and click on before adding an item to their shopping cart. After following the directions they can then continue to go about the regular purchasing process. At the end of the month Amazon.com and/or other similar sites send a percentage of each sale made to Green Any Site which then donates all of the proceeds to a charity or charities decided upon by bookmarklet users.
During the festival, Tal Ater, the founder and creator of GAS, showed me how it works. Here is the video: