Nice idea in theory, however my experience says such a list is an administrative nightmare. People who "opt-in" then have the responsibility of keeping the data current, which , even tho the user has opted-in is not likely to be done.

IMO a better method to "network" is on an adhoc basis.... make a post, wait for people to reply, build your network.. keep in touch with the people you want to, repeat while != satisfied. execute again as necessary.. :-)