The Supermag 244 kit comes with 72 long magnets and 108 short magnets. In total, that's about 11 feet of magnets.
Magnets are interesting to play with. I can take a
S==N and a
N==S magnet and move them together and they'll repel. If I put a metal sphere in between, they'll still repel until they both touch the sphere, and then they'll attract. Why is that? I don't quite understand it yet. The polarity of the magnets matters when building certain structures.
S==N (*) N==S and
S==N (*) S==N look and feel the same but when you're attaching more magnets to them, they'll behave differently. This page gives some tips on how to build with geomag/supermags. Unfortunately I haven't found any other web sites with magnet building tips. I did find an explanation of magnetic fields that was useful to remind me of magnetic and electric fields, and an entire site about magnets.
Something that I want to explore is combining Lego and Supermag. The spheres are larger than a Lego "dot" and the rods are narrower than a dot. Thus, you can hang the supermags off of a lego structure by creating a 1x1 hole in a structure, putting a supermag rod inside, and then putting a sphere on top to hold it there. Another way to use them is sideways―the length of a half-size supermag rod is about the same as the length of a 2-dot brick. One of these two orientations should be usable to build a maglev train. With 108 short rods, I can either build a monorail (3 dots wide) maglev that's 2x108 = 216 dots long (that's about 6 feet) or a dual-rail (5 dots wide) maglev that's 108 dots long.
The only thing I need now is magnetic viewing film.