one of the other for'ners working here at our uni did this on his folder w/20" wheels.
he was out riding through small towns and broke a spoke. no bike shops. the little
bike-fix-it guy with a stall on the corner did this trick. either no 20" spokes or no
cassette tool. due to other spokes breaking and brake track wear, he wound up buying
a new wheel after about 6 months. the z-spoke held that long at least.