I have thought about something like that...never actually came up with anything and you're right, it is a little strange looking. For some types of shooting, it might be pretty handy. I would definitely give it a try if I had a chance...$325 and up seems a little high though...might be worth it in some types of shooting...seems like all-day sports shooting might be the thing..but, it might be hot and heavy to wear all day though.
somebody else on that sportsshooter page just posted a link to a "gut saver" from Cabela's. Basically, it's just a pocket for a fishing rod that sets on your belt....a bunch of good ideas in that thread.