Brazil's Espalhe Guerrilla Marketing continues to stretch the boundaries of what you can do with a Facebook fanpage (following recent efforts such as its Facebook wedding, for Hall's) with another social-media stunt, this time for soft drink brand Guarana Antarctica. This time, Facebook fans get to send messages about their friends to the moon.

The campaign was launched on Brazil's "Friendship Day" (July 20th), which is also the anniversary of Neil Armstrong's landing on the moon. Until July 27, using an app on the brand's Facebook page, fans can upload messages honoring their friends and then vote for their top 100 messages. These will then be sent into space as part of Message To The Moon, a British initiative which is sending a capsule with messages to the Earth Satellite next year. The authors of the messages will get a special certificate from Message to the Moon.