Most citizens are not aware that legislation has been introduced in Congress that, if passed, could possibly end the U.S. Postal Service's practice of delivering mail door to door. The plan calls for the installation of neighborhood cluster boxes where postal carriers would deposit mail for several blocks of houses at a central location. Customers would then have to go to these locations with a key to retrieve their mail. Items too large for the receptacle may be handled with a notice to be picked up at the closest post office.