ok i know this is a little specific but i was looking at photography software for mac's and came across this tried this with friends nikon. as i only got to briefly use it please post your thoughts and comments on this software.
For those who are wondering what tethered shooting is its when you have your camera connected to your computer, you take photos and the photos show up on your screen and are immediately saved on your hard drive.
http://www.macupdate.com/info.php/id/31296/sofortbild
thats where i got it from..its free which makes it better.