  Carbon nanotubes have been famous since their discovery twenty years ago for
their remarkable physical properties, from strength a hundred times higher than
steel, to electrical current capacity a 1,000 times higher than copper. But so
far they have only been produced at most up to centimeter lengths.
  Here are presented some proposals to combine the nanotubes in such a way to
get arbitrarily long lengths while maintaining their extraordinary physical
properties.
