Correct me if I'm wrong, but I always thought that Heisenberg's uncertainty principle means you can't know both position and momentum of a particle at a time. This tells you only position (after the fact), but not momentum.
It's probably better than lugging a bucket of water. Once you get the wheel going (and assuming that it's full, so the water don't slosh around), I think it's not that much work.
I agree with c-dub that it's actually a very elegant solution.
I agree with c-dub that it's actually a very elegant solution.