We found this on Adrants.com:
To call attention to thew deplorable situation in Zimbabwe, [advertising agency] TBWA\Hunt\Lascaris collected trillions of dollars worth of worthless Zimbabwe currency to create billboards, flyers and wallpaper. The purpose of the campaign is to support the Zimbabwean Newspaper which has been slapped by the Mugabe regime with a 55% luxury duty tax making the paper unaffordable to most citizens.
The campaign is running in England and South Africa where it is hoped people will buy the newspaper to support its ongoing coverage of the country’s plight.
More photos from the campaign here