For John Mills, founder of $200,000, five-employee Mills Group Multimedia, a Web-site developer in Cypress, Calif., cash flow can be a huge problem. Most customers don't even think about paying him for 30 or 60 days. And the time between when his employees report their work done and when Mills actually receives a check can be as long as four months. But three years ago, Mills hit upon a simple but effective method for easing the cash crunch: invoicing his customers every week. He hasn't had a cash-flow problem since. If a customer is unhappy with the procedure and requests standard monthly invoicing, Mills complies. But the customer has to bring it up. "Getting paid is the name of the game," he says.