Going Paperless - Document Management System

I have been looking d<a href=\"http://en.wikipedia.org/wiki/Document_management_system\">ocument management system (DMS)</a> so that we can go paperless, as much as we can. We have to use paper, considering our goverment and various other complainces require us to maintain document in paper form. I am currently evaluating following DMS:

These are opensource and stable products. However, it takes little effort to install and customize both of these for following reasons:-

Once I implement one of these successfully, I would post details. Meanwhile, we have done following to reduce paper usage:

With these small changes, we are already seeing benefits. With DMS, I can imagine life would be lot easier when it comes to maintaing, reviewing and sharing the documents. Please share your experiences, perhaps there is a better system I can implement easily.