While it is not uncommon for electric bikes to have a front hub motor or for them to have batteries mounted on the rear racks, these are the first pair of wheels that I have seen with solar panels integrated into them. I think that the idea is pretty cool, and can't really think of another place on a bike where there is enough real estate for an effective amount of solar cells to be mounted. Wheels like these are likely a bit more aerodynamic, but could pose a bit of an issue if there are heavy side-winds. Still, with this bike you could pedal when the going was easy and engage the motor when the going gets tough - and all the while never need to gas it up or plug it in.
[Source: Therapy Products via Reuben Miller - thanks!]