gPhoto has a basic command line interface, which is handy, if you want to set up a web camera, and use gphoto in a script, e.g. with Perl/PHP.

gphoto

-n

display the # of pictures

-s # filename

save image # as filename

-t # filename

save thumbnail # as filename

-p filename

take picture and save as filename

-d #

delete image # from camera

-l filename

save live preview as filename

-h

display help screen

gPhoto configuration file