Would magnetic boots be an actual practical way to move around in microgravity, or would they be impractical?
In theory?
Could potentially work on any conductive surface through the creation of eddy currents in the material.
In practice?
producing eddy currents strong enough is likely to cause magnetic hysteresis of the material, and runaway heating, especially in thin surfaces where intense field strengths will be needed for good attachment.
The premise is that if you have a moving magnetic field, the induced field in the conductive surface will have interaction, and thus some level of attraction. This requires either a quickly oscillating magnetic field, or a mechanically moving one.
EG, spinning disc magnets in the soles of the shoes would do it, as would a rapidly oscillinating AC current winding.
Noteworthy problems:
The thickness of the conductive surface will play a significant role in how attracted the boots are to the induced magnetic eddies. There was a mythbuster's episode that dealt with this in naturally ferromagnetic surfaces-- the flux that can be generated is proportional to the amount of material being acted on. if the plate is really thin, you will barely cling to it at all, even with very powerful magnets.
Inducing a current through an oscillating current will induce very strong hysteresis, and will run the risk of causing magnetic induction heating in the surface. Unless you like to melt the surface you are trying to stand on, you are going to have a maximum allowable power rating going through the mag coils.
Mechanically rotating magnetic discs use very little power, but run the risk of acting like reaction wheels when not magnetically latched to a surface.
Youtube has plenty of videos demonstrating the interractions between induced magnetic fields and moving permanent magnets. The most poignant are the "neodymium magnet dropped down copper tube" ones. Basically, the induced magnetic eddies in the tube from the falling magnet partially arrest the magnet on its way down, causing it to fall very slowly, even though the pipe itself is nonmagnetic.