The "Addicted to Rubber Stamps" site closed a few months ago.
http://www.bizzaro.com/ has some offbeat stamps.
I've gotten some wonderful stamps from Leavenworth Jackson Rubber Stamps in Berkeley, California! http://www.ljackson.com/index.html The only problems are that they don't take credit cards and they don't take internet orders. It's all by snail mail and check or money order. If you take a look at their website though, you might decide that's it worth the wait. It was for me.
Plus, if you read all the way down to the bottom of their order form, there is a "readers gift" that you can order. I got a free heart rubber stamp with my first order. Also, they stamped my order envelope with stamps that were not in their catalog or on their website! Which made me want them too. With an email to them, I found out they were available and the price. I've ordered them too.
This one I ordered at www.naammo.nl