The Tofte Project is an award-winning green retrofit of an old cabin on Lake Superior. That's moderately worldchanging, but the project's website is fabulous (though flash-heavy and currently slow) and just won a Webbie. Goes to show that the presentation of sustainability information needn't be boring.
Nuts! I wish I would have run across this project before my folks built their cottage on Lake Superior! Thanks, though; there are still some great ideas for retrofit.