You can build your own bumper sticker too. Go check out build a signs web site (click here), they have many options to pick from. I am not computer savvy at all, but their design center was super easy to use, and it's really fun. You can upload your own image or choose from hundreds of their clip art options.
I should have some bumper stickers in hand soon, let me know if you would like one.
Email me your address at firstname.lastname@example.org,