This month, Apple Computer Inc. expanded its computer recycling program for U.S. customers. Those who buy a new Mac through the Apple store online or any Apple retail store will receive free shipping and recycling of their old machines. Dell's main rival, Hewlett- Packard Co., meanwhile, said Tuesday that it was expanding its product-recycling program with a series of summer collection drives. The drives, running between June and September in Colorado, Connecticut, Illinois, Maryland, Minnesota, New Mexico and Oregon, will let consumers drop off a range of electronic devices for recycling free of charge, the company said. Under Dell's previous policy, available since 2004, consumers could get free recycling of any brand of computer or printer only if they bought a new Dell system.