Hi Anthony, After I posted my question, I did some more searching and came across
"iPhoto Library Manager"
The link is to Brian Webster's home page - the library manager is under "Mac Stuff"
It's freeware and works well. It lets you have as many libraries as you want - where you want - but to switch between libraries, you have to quit iPhoto, switch, and then start again - I think he includes an AppleScript to do the stopping and starting. One limitation is still that you can't move images between libraries.
The problem I was trying to solve is that my digital camera names images "DCP_nnnn" and I found out from bitter experience that it's best to stick with the camera name. Unfortunately, when looking for a particular image, it means opening hundreds of images in
PS before you find the one you're looking for.
Photoshop Elements to the rescue. PSElements has a feature that lets you browse a folder of images and view thumbnails of the contents. You can't manage the images (move them etc.) but at least you can see them without opening every one.
I only have a free (Classic v 1) of
PSE that came with a printer or something, I don't know what the commercial version offers. Another bonus for me is that
PSE plays nicely in Classic whereas Photoshop 6 drags performance into the gutter.
Hope this helps, Margaret