Thanks to Eric for recommending Poblano on Roosevelt Avenue. Stopped by yesterday, had a 3-taco deal: Carne Asada, Chorizo, Barbacoa. Very fresh, clean, herby, and delicious. My only problem was that I don't speak Spanish and the waitress spoke zero English. She handed me a menu, pointed to the tacos and asked what I wanted. I tried an "una momento", but she clearly thought I should have known what I wanted. I didn't want to be culturally offensive, so I didn't dawdle over the menu.
This doesn't bother me at a chow joint; I'm not expecting Restaurant Daniel service. Just wish I had more time to see what was on the menu.
Eric's survey (which I ran across today) was also great. I could use a bit of a primer on real Mexican "street food," however. I may be a chowhound (I make a pretty intense mole poblano), but lack of availability of the real thing leaves me a little in the dark about what to expect from tortas, horchata, etc.