The obvious answer seems to be electric assist bicycles. They could be very geeky high tech, very efficient, good for the environment, and an excellent way to travel in areas with good weather. I've seen many attempts at making them but they're still burdened with obsolete tech that doesn't excite anyone enough to make the purchase. They need to lose the cheap heavy batteries, lose the bulky clamps and adaptors, they need variable regenerative braking, they need some vibration dampening, they need detachable storage, and they need theft protection. Public specifications would be a big help too so people can do their own hacks. Not only is that easy geek cred and comfort to buyers, but it's getting free R&D from the public.