VERSATILE CARBON NANOTUBES are (1) now observed to be superconducting. A group at the Universite Paris-Sud has detected the flow of supercurrents through single nm-wide nanotubes and through bundles of 100 nanotubes at temperatures below 1 K (Kasumov et al., Science, 28 May). (2) Nanotubes have been used to produce muscle-like actuators. A cantilever consisting of two sheets of nanotubes separated by a layer of Scotch tape could, when a voltage was applied across the sandwich, produce stresses higher than natural muscle (Baughman et al., Science, 21 May). (3) Nanotubes, which can be only nm in width but microns or longer in length, are expected to be an ideal strengthening agent in composite materials (Nature, 20 May.) Finally, (4) alkali-doped nanotubes are expected to be great for storing hydrogen, perhaps for use as fuel (Science, 2 July 1999.)