I think this is a Maltese, but I am a "big" dog person and don't know all the smaller breeds.
EDIT: Sharon says I am wrong, as most times - LOL - she doesn't think this is a Maltese, is there anyone that can confirm this dog breed?
(Note: I could not get permission to post this photo. If the individual in it prefers that it not be posted, I will gladly take it down and apologize. I was standing in a public place when I took the photo, so it was "legal", but, I have no desire to annoy anyone.)