If you don't already know, 'QR' stands for 'Quick Response', and QR Codes are these two-dimensional graphics codes which store a bunch of information on them that can be machine-read. They've been around for awhile, and they've been used for storing logistical information such as automotive parts, and on baggage tags and boarding passes at the airport.
Here's a bit more about QR Codes on Wikipedia.
Here at Minejima & Co., we're proud to be the local distributors of QR-coded Luggage, Key and Pet Tags by RuMeID, where the codes store just the URL that the finder of your lost and RuMeID tagged items will be brought to when he or she scans the unique code on their smart phones.
We think it helps a bit that RuMeID tags are colourful and attention-grabbing too.