Need a little love in your life? Skip the online dating sites and head to Petfinder instead. The Web's largest pet-adoption site lets you choose from more than a quarter of a million animals, searchable by age, location and gender. Each listing includes at least one photo and tells you whether the animal is house-trained and has had its shots. Many of the available pets come from a local branch of the Humane Society or a local rescue group, which will screen potential owners to make sure they can take care of the animal. Because only nonprofits are allowed to post listings, you won't find pets sold by breeders or pet stores, and many animals are fully grown. With so many pets to choose from, it may be tough to settle on just one.