Small? Yes. Cool? Probably. Useful? Not to most of us.
There are applications for devices like that, and I could think of a few that would warrant me getting one, if I had lots of extra money to spend. But at this time I would guess there is no compelling reason for 98% of the computer-using population to run out and buy one of these things. Hopefully they will get cheaper, and become more widespread. 🙂