Dont not forget best polymodeler Wings3d
and this tutorial for self made:
http://home.comcast.net/~chronosphere/tut-wings-bucky.htm
(plugin (geodome) from the tutorial are included in the latest version Wings3d)
after you can use tool "Importobj" recommended by Marc
or "ObjTo3dm" : http://dave-l.com/grafix/index.php?page=objto3dm