It seems that they are already testing concepts from Gantz; just look at those "round bikes" used by Will Smith on the Men in Black III film
lol that's the first thing I thought when I saw them.
stole the idea the cunts.
I wonder if Oku came up with it himself... who knows.
as i remember the real one was before gantz.
just found one: "...Almost a whole century ago, the Italian inventor M. Goventosa de Udine created a strange vehicle: a one-wheel motorcycle that could reach up to 150 km/h (93 Mph). The strange vehicle had one single large wheel, larger than both the vehicle and the rider. This idea from the early 1930′s didn’t take on..."
Though wikipedia doesnt mentions Goventosa http://en.wikipedia.org/wiki/Monowheel
^ on Gantz fb fan page somebody posted also a video : http://www.youtube.com/watch?v=rvA7hDh_vhY