So... how is this old fashioned?
Normally this would be done by meetings by which you meet people in the same room as you are... as people have been for thousands of years.
Of course I personally would insist on written proposals, as the ability to write a good proposal is probably corellated to the ability to write good specifications or software. All of those forms are text based and all require you to understand the core of the problem in a way that makes you able to add any special requirements. If you can do that, you can write both a good proposal and good specifications. If you cannot even write a good proposal chances are you are not going to be able to write good specifications to be implemented.