Interestingly enough, I just finished "The Lost Pet Chronicles" by Kat Albrecht. She recommends the following additional sites:
Information on lost pet behavior, listings of pet detective and search resources, and links to online volunteers who can provide unique tips, instruction, and emotional support through email discussion lists.
Find tips on how to search for and recover lost cats.
Site offers excellent information as well as post card distribution service, enabling owners to mail lost pet information to neighbors within a target search area.
Excellent tips on how to prevent your pet from becoming lost as well as how to develop a plan to ensure rapid recovery.
National organization that has set up community based pet services including lost pet web listings for your city.
Sells animal handling gear, including humane traps for both dogs and cats and amplified listening devices.
We list some lost dog tips in each adoption folder -- tell Mama she is free to print those in the blog if she wishes.