(Business 2.0) – NEW YORK

Hallo Berlin The self-proclaimed "wurst pushcart in New York" serves up juicy knockwurst ($3), bratwurst ($3.50), and weisswurst ($3.50). Regulars choose what proprietor Rolf Babiel calls his Dictator Special ($5 to $6): two sausages (of Babiel's choice) smothered in steak sauce, fried potatoes, onions, and red cabbage. Babiel got a letter from Chicago mayor Richard M. Daley's office inviting him to relocate, but the East German transplant refused to leave Manhattan. "I am used to da love und da hate," he says. At 54th Street and Fifth Avenue.

PHILADELPHIA

Mom's It may not be the legendary Gino's, but 17-year-old Mom's can't be beat for cheesesteak deliciousness per square foot of kitchen space. Folks line up at the small stainless-steel cart for the pizza steak ($3.50)--sauteed chopped beef topped with provolone and Harriet "Mom" Antanasiadis's homemade marinara, which is spiked with oregano and garlic. The Italian hoagie ($3.25) also ranks. Prepare to use every inch of the five or so napkins wrapped around each order. At Sixth and Chestnut streets.

CHICAGO

Vee Vee's African Restaurant Feeling adventurous? Try traditional egusi stew ($8): spinach and tomato set atop mixed--and we do mean mixed--meats, including cow feet, goat ribs, and tripe. "Before sucking on a cow bone," one customer advises, "you definitely want to do that tie-flip-over-the-shoulder maneuver." Your first Nigerian food experience from this pickup truck turned food stand, however, needn't include mystery meat. Order the tomato-heavy jollof rice, which can be spiced to taste, or the fufu made with pounded yams ($5 each). On Columbus Drive, near South Water Street (among other locations in the Loop).

AUSTIN

Nuevo Leon Taco Express Need to grab a quick bite before the first appointment on your calendar? Forget muffins--in these parts, tacos are breakfast food. Egg and cheese, potatoes and cheese, and sausage and egg, among others--your choice for a buck apiece (two tacos make for a hearty meal). The chunky pico de gallo salsa is homemade, and the tortillas are prepared on a comal (flat grill), imparting the slight crunch you just can't achieve by microwaving. But get in line behind the white Chevy van early: By 8:30 a.m., there's usually no mas. At West Fourth and Lavaca streets.

SAN FRANCISCO

Happy Sushi to Go Raw fish off the street? Inside his camper-size vehicle, owner and Okinawa native Tsutomu Tomita has a high-end refrigeration system and ingredients from top restaurant suppliers. Every piece of sushi is made on the premises, resulting in tekka maki (tuna roll, $4.50), assorted nigiri ($7), and shrimp tempura rolls ($5.50) that taste restaurant-fresh--even after a walk back to the office. Create a small feast with tea ($1) made from goya, a squash-like vegetable, and miso soup ($1.50) rich in big bites of fresh tofu, not the rehydrated kind. "I want people to enjoy real Japanese food from a truck," Tomita says. "That is my dream." On Bush Street, between Montgomery and Sansome streets.

--ANDY RASKIN