OK, basically have a look at the ID Imager application. Then do that with much better speed, better UI and less bugs...;-) That is the only application that is doing it almost fully now.
Currently I am using PM for everyday waork, then IDI to catalog images for later use: printing portfolio images, website etc. The problem is that the best images usually end up having multiple versions in the database. The original RAW file. The edited, the TIF and JPG delivered to the customer. Then the versiopn cropped for portfolio print, the web version, then a year later I probably decide that the portfolio print is not good enough and reprint it a bit darker etc etc.
The trick here is to be able to treat these images both as individuals and as ONE when needed. Each version should keep a reference to all the others. So when I have one thumb I can easily see in a side window all existing versions as thumbs of that image too.
IDI has a bunch of user editable labels/positions so you can tag the versions. I have for example these tags/categories: Original RAW, Edited PSD, Delivered TIF, Delivered JPG, Web JPG, Portfolio Print, and then IDI allows me to ahev a bunch of untagged versions too.
One thing that IDI does wrong according to me is that in a "Collection" of files only ONE version may exist. You can select in the versions window which one you want, but thats not good enough. IDI also has something called "Fast Collections" that allow you to have several versions visible in the collection, and that is the right approach I think. (But "Fast collections" are not stored in the database, so of limited use.)
Then there is the means of finding the verisions, ín IDI there is a bunch of search script available, including look for simillar colors etc etc. I have written a script myself that looks for the longest number in the filename and find files with that same number in the filename (I always keep the original filenumber somewhere in my renamed files).
So, I could write an essay on this...;-)
Let me know if you want more input. Like I said, if you do this well you will beat the competition hands down. There is a lot of talk about versioning in the DAM world, but little available. (IMatch has promised veriosning for some time now). Veriosning keeps me using a slow and buggy application like IDI, it is so valuable when you access your old images!
Rgds
PM