The Zimbabwean newspaper makes an original suggestion:
From their Flickr stream:
Trillion dollar flyers and posters. A trillion dollar hand-out. To highlight the plight of Zimbabwe and the cause of the ‘Zimbabwean Newspaper’ we handed out trillions of dollars of worthless Zimbabwean money stamped with provocative messages and a call for support for the Zimbabwean newspaper, we also turned the money into giant posters, with trillion dollar tear-offs.