Surface Tension

Surface tension in the kitchen sink. At Berkeley Lab's Molecular Foundry, scientists study surface tension to understand how molecules "self-assemble." The coin trick in the video uses the re-arrangement of water molecules to seemingly create order out of disorder. The same principle can be used to create order in otherwise hard-to-handle nano materials.

Scientists can then transfer these ordered materials onto surfaces by dipping them through the air-water interface, or (as we've recently shown) squeeze them so that they collapse into the water as two-molecule-thick nano sheets.

I found this one on the Physics and Physicists blog.