Show us a successful restaurant, and we'll show you an owner who knows how to control costs. But few restaurateurs go as far as David Ludtke, who has built his entire restaurant around keeping costs down. Customers at his Hourglass Tavern in Manhattan's theater district turn over an hourglass when they sit down to eat. An hour and 15 minutes later, the sand runs out, and mealtime is up.

Ludtke says he opened the restaurant with the goal of "keeping volume up and overhead down." He con-sidered buzzers and alarm clocks but decided the noise would drive people batty. The hourglasses are silent, attractive, and efficient (although they do slow down in humid weather), and people like flipping them. In return for their cooperation, customers pay only $11.50 for a three-course meal.

The tavern seats only 23 people, but Ludtke claims he can turn his eight tables four times on a busy night. To hold food costs down, he offers a limited menu, and the small space keeps labor costs low.

In its first year, the eatery took in about $150,000 in sales, he says. Did he make money? "Yes, but I'm not going to become a millionaire from it." Nor is anyone else: Ludtke has trademarked the logo, the design, and the name Hourglass Tavern.

But does he really ask customers to leave if they haven't finished after 75 minutes? "We will if we have to, but we're not heartless. I didn't open a restaurant so I could throw people out."

-- Joshua Hyatt