I don't know whether these have been covered before (probably)
but the pm's listed more like a conversation or at least a "sent" box. It can become a bit confusing when you can't see what you said three or four messages back etc.
The other idea would involve google maps (or other?)
but you could have a members map and a meet & events map.
Members could tag themselves in a certain area by town centre (not your actual address) then you can see how many members are in your local area and arrange meetings etc etc.
The other map would be based on meets. Each meet could be tagged in a map stating date and time and location. Then all you need to do is look at the map around your local area to find out if there are any meetings or gatherings and then attend.