I am currently running Coppermine Photo Gallery 1.4.25 (stable).
I use this as part of my photography business. What I do is normally send out a password and link to client to view there images but is it possible to display the album on the main page to the public with perhaps a padlock as the thumbnail?
My Gallery is loaced here: http://clients.deviantphotos.com - At some points it may contain images of an adult nature.
Thanks
Dave
Change the config option to show hidden albums - http://coppermine-gallery.net/demo/cpg14x/docs/index.htm#admin_picture_thumb_advanced_private_icon_show