Accepted Wednesday Sep 16, 2009
We review our understanding of the "long-range" electrodynamic, electrostatic, and polar interactions that dominate the organization of small objects at separations beyond an interatomic bond length. From this basic-forces perspective, we describe a large number of systems from which we can learn about these organizing forces and how to modulate them. We then survey the many practical systems that harness these nanoscale forces. Our survey reveals not only the promise of new devices and materials, but also the possibility of designing them more effectively.