SLR film cameras have a shooting button that can take a shutter release
cable. I haven't seen this on a digital camera. For production work like
catalogs or yearbooks, you'll want to command the camera to take a picture
and send it back to the computer immediately. This would be the digital
equivalent of the cable. Very handy for repetitive shooting.

Has anyone seen a combination of camera and Linux software that can do
this? Thanks.