The really nice thing about this calculator is that it can be embedded right into any website, they just ask for a little props on the page. With a little html/css knowledge, you can have this baby chugging along on your guild/fanboy website! They even have a page that explains how to style it, and they give a few examples.
I can't wait to see if they guys over at WoWHead.com come out with even more great tools!
[From tipster Silvertusk]