Looks cool, but when you think about it rationally, it's kind of lame. If you are going to everyday carry a firestarter, you may as well carry a proper lighter which is convenient to light fires with. As others have said, a peanut lighter is also small enough to carry on your keychain, It's 'O'ring sealed watertight and carries it's own fuel supply, so instant fire. The sealed lid keeps unused fuel for months on end.
....And, if you do use your fuel up (actually lighting fires, rather than your one stored tinder piece), you can still use the flint wheel to produce sparks just like the nanospark. A couple of extra flints can be stored in the fuel compartment and in an emergency, when your fuel and tinder are all gone, you can pull the wadding out of the fuel compartment and use that as tinder to take a spark. - I have experimented with this, and the wadding takes a spark much more easily than the tinder quik-style tinder.
A Chinese peanut lighter will set you back maybe a couple of $. Or you could have a nice County Com Peanut or Split Pea in varying sizes and materials including copper, brass and titanium for about the same price as this one trick pony.
Finally, the flat bottomed ones can also be used as an emergency candle light.