I've been watching the Ewan McGregor/Charley Boorman series 'Long Way Down' again. It documents a motorcycle journey the two of them took from John O'Groats, Scotland to Cape Town, South Africa. I'd really enjoyed Long Way Round, which took them from London to New York traveling east and I think this was actually a little better. Or perhaps it was just better editing. I think their team had a bit better idea what they were doing anyway.
Nevertheless, the idea of putting in those sorts of dizzying miles on a bike is ridiculous. The idea of doing it in Africa just seems suicidal. Cool show though and definately worth a view.