A friend will be visiting DC this friday, arriving at the Capital Hilton on 16th and K at around 11-11:30 pm. He's going to be starved, and I wanted to point him out to a nice place to eat close by. I've read conflicting reports about El Tamarindo which is open pretty late. In terms of cuisine - burgers and whatnot are ok, mexican/south american preferable, but ANY suggestions are very very welcome! C'mon Chowhouders, let 'er rip!