The one which really stood out from the QR code crowd was this great campaign by UNICEF Thailand.
They created a poster campaign which was placed on Bus stop billboards across Thailand. These posters contained no images Logo, or Text. Just a plain black and white QR code.
When you scan the QR code the message “You have taken the first steps to provide well for drinking water” pops up on your phone. You are then led to a donation page which allows you to donate directly to UNICEF.
Source Sharon Chan