When a number of my colleagues were at the Pole during the early part of this year, they installed a webcam behind our firewall there. As such, I've been able to watch the sun go down over the past week. Once below the horizon, the sun won't rise there again until 21 Sep 2007.
The pictures below show the sun heading below the horizon, the sun on the first day it is below the horizon, and the sun several days after it set.
The photos are blurry because the webcam is focusing on the dome that encloses it, rather than the objects at which it is pointed. In addition, some snow and ice is sticking to the dome, so that introduces some artifacts into the photos.