Recent developments in nanotechnology and the demonstration of various quantum size effects in nano-scale particles, implies that many novel devices of the future will be based on properties of nanomaterials. Reports of zinc oxide (ZnO) nanostructures, especially nanowires, are of interest due to their potential applications in gas and chemical sensing, micro-lasers, field emitters, amongst others. Also reported for ZnO nanostructures (piezoelectric material) are applications as cantilevers, with size scales over 50-100 times smaller than the conventional cantilevers, which show improved sensitivity and mechanical flexibility for applications in scanning probing microscopes. Wide ranges of strategies have been explored by different groups for the synthesis ofnanowires of ZnO. The conventional synthetic techniques for ZnO nanowires usually involve a high temperature, vapor phase synthesis. It is a catalyst-based synthesis that relies on the dissolution into metal nanoparticles (usually gold), super-saturation and crystallization of the vapor of the semiconductor material like ZnO. Various modifications of the hightemperature vapor-solid method have been reported for the growth of ZnO nanostructures, including nano-belts and nanowires. The commercial potential for these processes are constrained by the need for an insulating and/or expensive substrate for proper oriented growth of the nano-rods, and also the complexities and cost of the high temperature and vacuum systems. The need for deposition of a monolayer of gold nanoparticles on the substrate, to catalyze the epitaxial growth, further increases the complexity of the process. Other techniques to synthesize nanowires of ZnO include template assisted growth and electrophoresis. Alternative techniques for synthesis of nanowires of metal oxides usually involve a hydrothermal growth process inducing an epitaxial, anisotropic crystal growth in a solution. The hydrothermal process is usually substrate independent and offers a fairly good control over the morphology of the obtained nanowires. Among the various synthetic techniques for obtaining nanowires of ZnO, the sol-gel based strategy involving hydrothermal growth of ZnO particles is probably the most energy efficient, by avoiding the complexities of vacuum environment and the need for high temperatures.