I was playing with ball bearings and small cylindrical magnets. The balls were 3/8" in diameter and made of CRS. The magnets were 1/4" in diameter and 1/8" long. When I let the magnet go while in contact with the bearing, it would nicely center itself.
Then I lined up a series of bearings that were touching. I took a piece of scrap MDF and drilled snug holes for the magnets with a spacing of 3/4". I was able to slide the MDF over the bearings (magnet side down) and it would jump into alignment just like snapping to grid in a CAD program.
Fun idea but, at the moment, I don't have a good use for it.