Why pay for something you could do yourself for nothing?Perhaps you've seen the ads for biweekly mortgages, or equity accelerator plans, which enable you to shave years off your mortgage for a one-time enrollment fee and monthly transaction charge. But these biweekly mortgages aren't loans -- they're payment plans that charge you for something you could do yourself. And their popularity is growing. Go figure. "We're seeing a huge jump in it," says Chuck Hilbert, content and media manager with Paymap, an electronic payment services company that administers equity accelerator plans for financial institutions such as Citigroup, Banc of America and Washington Mutual. In February 1999 Paymap had 168,500 subscribers for its equity accelerator product. Three years later, 512,500 people have signed up. "As more people hear about it, we get calls asking if they can do it too," he says. Paymap and other service companies work as middlemen between banks and customers, processing payments and handling the back-office paperwork. Banks get a cut of the revenue obtained from fees that service companies charge homeowners. Because of the profits and increased customer demand, banks have become more interested in Paymap's services. "Three years ago, there were 21 major banks doing this with Paymap," Hilbert says. "Now we have 32." Countrywide Home Loans offers a biweekly payment service, but instead of using a service provider like Paymap, it administers its own equity accelerator plan. Denise Sandoval, vice president of payment services, estimates the company has 18,000 customers on the service, called PayPlan26, with more than 2,000 signing up each month. "It's growing by leaps and bounds," she says. Under PayPlan26, Countrywide customers don't have an enrollment expense but do pay a $2 transaction fee per month to cover the cost of the program. The cost-savings benefit of moving lick-and-mail customers into an all-electronic service, combined with the transaction fee, covers the cost of the program. "As far as this being a profit center? I'd say no," Sandoval says. At Bank of America, about 50,000 customers are enrolled in one of the company's biweekly payment services, according to Julie Davis, a company spokesperson. Davis could not quantify an increase in enrollment but says interest is rising because customers like being forced to budget -- especially during a recession.