In the last decade, one-dimensional carbon nanotubes have attracted the attention of a wide range of scientists due to their unique morphology and nanometer-size scale, as well as their versatile physical and chemical properties.[1-4] Their intrinsic properties make them useful in a wide range of potential applications including nanocomposites, energy-storage and energy-conversion systems, sensors, field-emission displays and radiation sources, nanodevices, and probes.