They have a truck, but opened a brick and mortar last year midtown east, on 3rd somewhere. Yummy yummy!
Also, I forget the name, but a falafel place opened up on the west side of lex between 55th and 56th (90% sure those are cross streets, could be a block up or down). Anyway, I know falafel as it's a family business in Israel. This is one of the few places I've tried outside of Israel that has a decent falafel. Cheap too.