  The formation of quantized vortices in trapped, gaseous Bose-Einstein
condensates is considered. The thermodynamic stability of vortex states and the
essential role of the surface excitations as a route for vortex penetration
into the condensate are discussed. Special focus is on finite-temperature
effects of the vortex nucleation process. It is concluded that the critical
angular frequencies for exciting surface modes with the relevant
multipolarities yield, also at finite temperatures, the appropriate thresholds
for the nucleation of vortices in dilute Bose-Einstein condensates, in fair
agreement with the recent experiments.
