We glued magnetic balls to the ends of 50 cm long sticks, and they worked remarkably well as building materials. We decorated our stand with posters showing polyhedra in art, architecture, science and everyday living, and we also constructed a newspaper geodesic dome that we placed on top of our stand (see earlier post for instructions). We had three tables and a carpeted area for building. For two days we built stuff with kids and it was fantastic fun.
Here's some pics of the construction process. We bought flowers sticks from a craft shop and Bucky Balls, strong magnetic balls that are awesome to play with by themselves. With a glue gun, put a small dab on the end of a stick, press a ball into it, and after it has cooled place a small amount of glue on the seam and then rotate the stick while smearing the glue around the seam with the tip of the glue gun. The glue should reach up the the midpoint of the sphere or a little higher. If done properly (it takes practice!) there is only a small amount of glue but the magnet is fastened strongly to the stick.
To be determined by further research: is it better to have the poles parallel or perpendicular to the stick? My feeling is that perpendicular will make for a better building experience. The first picture below shows the magnet being attached parallel to the stick. This gives less opportunities for sticking to other magnets, though the attraction will be stronger when it does align. I am unlikely to build another set so I may not know, but should you wish to make a set, you might want to try both and let us know!