Several years ago the Massachusetts Animal Coalition started a fund raising program involving car license plates.
You maybe have seen these plates with S/N (for spay/neuter) followed by a number. Also on the plate is a picture of a cat and dog and at the bottom of the plate the words "I'm Animal Friendly" are written. Funds generated from the sale of the plate and renewals are used to help fund organizations that offer low fee surgeries for animals. They typically raise around $150,000 in proceeds per year and have spayed or neutered well over 20,000 animals since the program has started. The plate does cost more than a traditional license plate but the extra money is much needed for our animal friends. You can learn more at www.petplate.org.