What is the origin vuvuzela, the famous and noisy stadium horn from South Africa during the World Cup ?

Vuvuzela is an instrument, but not always a musical one... For most people watching the world cup on television, its rather anoying....but in the same time, describing the atmosphere in a stadium packed with thousands of fans blowing their vuvuzelas is difficult and impressive...
Ok; but you probably wonder where Vuvuzela comes from ? What is the origin of this dumb horn / trumpet ?

Guess what... we have finally found the answer just for you :