Technology is almost there not too expensive, you can get hydrogen just by sticking two wires in water and from the negative end hydrogen bubbles are made and from the positive end oxygen bubbles are made. Did it in high school with a 12 volt DC power pack.
Basically when you put them back together in the required circumstance they release plenty of energy the only by product being water.
There are also some other problems but they will be ironed out easily in the next 5-10 years/
The major problem as I stated before is the storage problems of hydrogen, because its molecular mass is so little you cant get alot of it in a small space but it still takes up relatively the same amount of space as larger elements, pretty much everything (hydrogen is the smallest one). I think what im trying to say is it has a very low density. So if you stuck it on a car you would get lets say 50k's of one full tank maybe even less at the current fuel efficiencies of them. (I dont know the exact figure).
The fuel efficiency on a scooter is 40km/L at the least. On average on a car about 9 if your lucky. As you all know i am sure.
So taking all this into account i was thinking it might be possible to strap one on too a scooter and see how it goes. Just for kicks ofcourse mainly cos you cant refuel it wherever you like, and there is no support. And i was just wondering if someone has had a go at it. As i know plenty of weird stuff done to scooters like the one covered in solar panels with two giant solar wings.