The always-fun folks at Simple Shoes just announced that — in honor of Earth Day — they are giving away a free pair of their Stop Global Warming flip flops with every order.

So, it’s a great time to pick up a new pair of eco-sneaks, sandals, mary-janes, or any other of their environmentally friendly and fun-to-wear products. There are lots of shoes and bags on sale now, too, by the way.

To claim your free shoes, just add one pair of the Stop Global Warming Toepeeka flip flops (style 2043 or 9189) to your cart, along with at least one other item, and enter the promo code HappyEarthDay09 when you check out. This offer is valid from now through May 31, 2009.

So, click on over to Simpleshoes.com and start shopping!

Update (6/1/09): This offer has expired.