I got mine from Griot's Garage and they were installed this winter and do dual duty as cup holders and covers for my old vent holes. I can report that they are truly excellent.
I just stumbled on a cheaper source for the same thing that includes a little animation of how they work. I don't l know why they included the little spin at the beginning of the animation. They should have left that out and slowed it down instead.
http://www.ultimatecupholders....ischercupholder.html
With my black interior, these are pretty much invisible when installed.