CES 2013 - FinderCodes, a new startup that has partnered with AT&T, uses QR codes to facilitate the returning of lost devices. Stickers or other tags can be attached to devices, key rings, luggage, or really anything that can be lost. If a device is found, the QR code can be scanned or the code entered on a website. The video below explains the returning process:
It's pretty cool and seems like it could be something that really catches on. They currently have about 2000 tags registered and some devices have already been returned using the service. FinderCodes has partnered with both AT&T and FedEx, so the company should be around for a while.