Birraporetti's, 3333 Bristol St. (in South Coast Plaza, near Sears), Costa Mesa. Open from 11 a.m. daily. Last call is 1:30 a.m. (714) 860-9090. A gleaming, upscale watering hole with lots of room to stretch out and a hassle-free environment. It attracts a somewhat cosmopolitan clientele, but if your idea of a bar is to jockey for room along with lots of vivacious, talkative people, well . . . have you thought of moving to Chicago?