Suppose we want to see the image of a delicate or enclosed space which is ordinarily inaccessible (see, for example, the article: New robots may aid Old Ironsides). Ideally, we would want a completely untethered floating camera. Let us examine the possible implementations of such a platform: (i) A miniature helicopter of some sort would create a downdraft, and would be extraordinarily difficult to construct. (ii) A lighter-than-air vehicle would have a low payload to volume ratio. (iii) A magnetically suspended platform has neither disadvantage (as long as the material to be inspected is not ferro-magnetic).
The Levitron is a toy which consists of a small spinning top which floats in the air, magnetically suspended about three inches above a static magnetic base. The top can be kept suspended indefinitely if small periodic magnetic pulses are present in the base (to keep it spinning).
My long term research agenda is to build on this principle, to make the top able to move around freely in x,y,z, to expand the workspace by getting the top to rise higher, and eventually to attach a miniature scanning camera and transmitter to the top, so that this technology can be used to explore delicate otherwise inaccessible locations and cavities.