Phlogiston: you have a very good point- however may I point out there is a rare condition known as
diphallasparatus or literary double dick syndrome (yes 2 peni). Depending whether or not you think having 2 cocks is an advantage or disadvantage- this could either be the best disease out there or the worst freak condition you could be born with.
There were actually a couple of Dutch videos made staring dudes with this condition called 'man met twee pikken' (I believe a few installements are still out there); in the one I saw, one guy said the only downside was that it was difficult to get an erection.
Oh- and I was looking at my avatar and I noticed it moved. Has anyone else seen this? Or did I imagine it?