Simple Solution offers products dedicated to removing pet stains and odors indoors, outdoors, and pretty much anywhere you can think of. They have a great pdf printable coupon available here. You should be able to print it as many times as you need and it doesn't expire until 5/31/11. 

What's even better is that, through 11/28, PetSmart has all Simple Solution products on sale for 25% off. Combine this sale with your coupon to get an even better deal!

Go here to print your Simple Solution Coupon!