I suppose, theoretically, that if the 'duplicate layer' command is scriptable AND is capable of moving the different files to one and the same document with a given name, it should be possible. On the other hand, if you are on Mac, this might be something AppleScript could do. I recognize this situation. Carefull placing is the thing that makes me use the mentioned 'duplicate layer' command that you can find in the layer palette. I am afraid the contact sheet with 1 row and 1 column will not work, because it makes a new document when the selected folder contains more images then can be put in the given rows and columns. Another problem is that it changes the size of the pictures. But the beginning of what happens is what you want. But I am not sure if the Contact Sheet script is the same as an action. I think I will do a google search, because now I am wondering myself. Maybe I'll be back...