One of the most visually impressive recent discoveries in physics is the phenomenon of quantum levitation, in which a superconductor becomes suspended within a magnetic field. Quantum locking goes even a step beyond this. This isn't the same as just magnetic repulsion, though, because the superconductor itself doesn't have any electrical charge. Instead, it repulses the magnetic field around it, but if the superconductor is thin enough, then some of the field pops through the material due to the quantum Meissner effect. The result is that the magnetic field actually "locks" the superconductor in place relative to the source of the magnetic field.
Physicist Boaz Almog from Tel Aviv University recently gave a TED talk where he demonstrates the phenomenon. It's available on our list of TED physics videos. (Though it may not be quite as cool as when Stephen Colbert quantum levitated ice cream.)
Image Source: Tel Aviv University superconductor group