I recently read an article in the AVMA (American Veterinary Medical Association) journal about "search methods that people use to find owners of lost pets."
This article highlighted the results of a survey done of 188 individuals who found lost pet in Dayton Ohio.
The results of this survey showed that only 38% of pets were reunited with their owners. The most 5 common method pet owners were found included:
One thing that I noticed is that most people that found a pet did not realize that it is free to advertise a lost pet in most local papers. This was the #2 method of reuniting pets. If you find a pet – be sure to advertise with your local paper!
JAVMA, vol 230, no. 12, June 15, 2007, page 1835 – 1840.