People who want to recycle small electronics can do so free under a test program at about 1,500 post offices.
The Postal Service is testing the program in several states and, if it is a success, may make it national this fall.
Postage-free envelopes are available at the test offices for people to send in old cell phones, personal data assistants, MP3 players, inkjet cartridges and other small electronic items.
Clover Technologies Group pays the postage and then remanufactures and remarkets the items. If the item cannot be refurbished and resold, its component parts are reused to refurbish other items, or the parts are broken down further and the materials are recycled.
It's an environmentally friendly way for people to dispose of outdated items they no longer want, postal officials said.
The tests are under way in several cities in California, Chicago, Washington, D.C., northern Virginia and Baltimore, Md.