Petfinder is the largest online, searchable database of animals in need of their forever homes. The site is updated daily and has listings for nearly 200,000 adoptable pets, simultaneously providing you with a directory of over 14,000 shelters across the US, Canada, and Mexico. If you're interested in adopting a new doggie (or any other type of pet), you can search their database by breed, age, size, gender, and location. There's even a personality / temperament assessment and picture preview of most animals. Petfinder makes it really easy to find just what you're looking for and, best of all, the service is totally free!