"...According to this report, the Mexican government says 61 U.S. banks and 798 U.S. police department accept the "matricula consular," a laminated card with a Mexican citizen's photo, name, address in the United States and date and place of birth in Mexico...."
I found that here (but there are a great deal many other locations that have information on them):
http://usinfo.state.gov/regional/ea/chinaaliens/innewsaug02.htm