The control of nucleation site size and density for An catalyst-driven growth of GaN nanowires is reported. By using initial An film thicknesses of 15-50 angstrom we have shown that annealing between 300 and 900 degrees C creates An cluster size in the range 30-100 nm diameter with a cluster density from 300 to 3500 mu m(-2) Conventional optical lithography to create parallel Au stripes shoes that a minimum separation of similar to 15 mu m is needed to avoid overlap of wires onto neighboring lines with our growth conditions that yield wires of this same length. The GaN nanowires exhibit strong band-edge photoluminescence and total resistances of 1.2 x 10(8)-5.5 x 10(6) Omega in the temperature range from 240 to 400 K, as determined for the temperature-dependent current-voltage characteristics. (c) 2006 Elsevier B.V. All rights reserved.