go here QR Code 2D Barcode Generator

enter your contact info like this
IF FOUND, PLEASE RETURN TO:
full name
address line 1
address line 2
phone number

print the barcode and tape it to your phone/CR-48! If you lose your phone/laptop and the person who finds it has a smartphone, they'll definitely be curious enough to decode the barcode and see your contact info.

for people who don't know what a QR code is, it's a 2D barcode that stores text. they are generally used to share links to websites

I was going to post an example of the barcode on my laptop, but I don't want people scanning it :P