The “Mail Back” program provides free postage paid envelopes at 1,500 post offices to mail back inkjet cartridges, PDAs, Blackberries, digital cameras, iPods and MP3 players. It's like Netflix...except you get back a cleaner environment in return (although we're personally more partial to donate our unused electronics, if our electronics were broken and unusable, this makes it easy to rid of them without worry).
Postage is paid for by Clover Technologies Group, a nationally recognized company that recycles, remanufactures and remarkets inkjet cartridges, laser cartridges and small electronics. If the electronic item or cartridges 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. Clover Technologies Group has a “zero waste to landfill” policy: it does everything it can to avoid contributing any materials to the nation’s landfills.
Further details here.