We have two rescued chihuahua mixes. Although they (especially one) cause some frustration, they are a joy to have, and are definitely part of the family.
The first thing that comes to mind is a post by my friend, about National Dog Day, back in August: about her dog, Tootsie, finding her forever home.
I also wanted to draw attention to the Northern California Chihuahua rescue (please forgive their terrible web design).
Also, of course, the Centre Country PAWS shelter where we got both of our furbabies.