This was loosely copied from a paper holder that a coworker bought a decade ago. The holder contains two small (half-inch) steel balls that provide enough friction to hold a piece or pieces of paper. Magnets are stuck to the back so that the holder can attach to a fridge or other magnetic surface. Paper can be pulled out but will not fall with the force of gravity.
Requires a little bit of cleanup with a razor. Place two steel marbles into chamber and seal by snapping back clip into place. Stick magnets to the flat underside in order to be able to attach to metal surfaces (I used self-adhesive magnets).