Guinness beer glass that reveals a QR code

QR codes have been a popular addition to marketing campaigns in recent years. Now BBDO New York has created a QR code on a beer glass for Guinness.

The QR code is only visible when the glass is full and when scanned it "tweets about your pint, updates your Facebook status, checks you in via Foursquare, downloads coupons and promotions, invites your friends to join you, and even launches exclusive Guinness content.'

A great promotional gimick and use of QR codes.