Yamo Thai Kitchen is open Mondays through Saturdays from 11am to 9:30pm. It has a very small, long counter and two small tables in the back. I went with a friend of mine, ordered a couple Thai dishes for lunch, sat down at one of the two small tables in the back, and enjoyed their food. The Thai food was very good and tasty, and you can get good value with the lunch prices offered till 3pm.
It's probably as close to Thailand as my friend will ever likely get to, since he seldom can afford a vacation.
BART San Francisco 16th St/Mission St station.