UK mobile network Giffgaff are all about providing top notch refurbished phones and shiny gold goody bags that give their customers extra data.

We were faced with a triple challenge: get people to donate their old phones, using only OOH media, and show how Giffgaff gives back.

We solved the problem with an unexpected solution: giant golden toilets. And we ended up bagging ourselves a pencil. Not too shabby for a lavvy.