"Eat Rite or Don't Eat At All." So it says on the coffee cups (and the souvenir T-shirts) at this no-frills 24-hour greasy spoon amid the industrial wasteland between downtown and Soulard. Folks come from miles around to fill up on the breakfast-and-burgers menu: bar-hoppers and club kids finally coming down from their late-night-into-early-morning highs; factory workers and blue-collars getting off graveyard shifts; curious newcomers who've heard about the bizarro vibe that pervades these cramped counter-only environs. To call the food at Eat-Rite cheap is an understatement -- six burgers (real-size, not White Castle-size) run $4.50. And many swear by the Eat-Rite's redoubtable slinger (for the uninitiated, that'd be fried eggs, hash browns and a burger patty, avec chili).