I recently wrote an article about the PINK THAI ID CARD for foreigners in Thailand. I was surprised that just this week, I used it twice: at hospital instead of my passport, and also to visit an inmate in jail.
It is used the same as a Thai ID Card for Thais. And remember that this is their most important ID.
It is quite easy to get and I would recommend any foreigner in Thailand to try to get it.
The article is here: http://www.isaanlawyers.com/pink-thai-id-card-foreigners-thailand/