It seems a little bit ridiculous that they're selling this as a "greener" and healthier alternative than a bicycle. I suppose the advantage is the size?
Absolutely agreed. Even just considering the energy it takes to keep its battery charged, I'd be deeply skeptical that this device would hold the lead for more than a few months, even if the manufacturing energy for a bicycle is higher -- and if you care about keeping the manufacturing energy of your bike to a minimum, you can buy a bamboo bike, or (even better) buy one used, something for which there is no equivalent with this device both because it's new and because I can't imagine it could hope to last 20 years the way a good bike can. And on yet another level, I'd also have to be convinced that this thing can facilitate car-free living the way bike ownership in an urban area can, which is a huge source of energy savings that bikes can bring to the table.