I always look at our local shelter's site for dogs.  Before we got Loki, I looked for 6+ months at the shelters for a Yorkie. I think I ended up finding and applying for two.  One I never got called back and when I called they said I lived too far away (it was like 40 mins) and other people lived closer, so they could do a home visit easier.  The other one needed to be adopted with his "brother" another type of dog.  I have allergies so I couldn't take the other dog too.  Plus, we don't have a fence and only wanted one dog.  In 6 months those are the only Yorkies I could find.
 
Recently our local shelter (
www.adoptpetshelter.org) found a hoarder/breeder with 22 yorkies and silkies.  They announced it on their website but didn't end up putting many up on their website for adoption.  The ones they did put on there (so far) have training/social problems (fixable!) and stated that they can't go into a home with another dog, or with kids, or with kids under a certain age, etc.  MOST of the dogs on their website say no kids under 8.  Well, since my husband and I are a young couple, without kids YET, we are out of the question.  My husband is even home ALL day because he works from home, but we don't have a fence because we live in a townhome (Loki is NEVER off leash and never unsupervised outside and we walk every day.) So that is another strike against us.  Every time I see a dog I fall in love with, the restrictions take me out of the running. 
 
  
My other problem is that I HAVE to have a Yorkie.  I have allergies and I have had problems with friends' dogs that most people are OK with, even poodles and bischons.  Yorkies and shih tzu's I'm great with, and hubby doesn't want shih tzus 

  Yorkie lover that I am, if I had no allergies I'd have a black lab. 

  And I would have gone to vet school!  (Those cat allergies are the worst!)  So for all of Loki's craziness that I deal with, I love him so much more simply because I can have him!