One of the most interesting things I have heard about Destiny is it's ability to connect people and allow players to randomly meet each other playing campaign, multiplayer, etc. Social interaction definitely seems to be important but I really think this game should allow players to be able to actively trade with each other. Lets say you find a cool weapon somewhere and someone else wants it, you could trade for a new cool weapon. Lets say you are pinned down and out of ammo, maybe your co-op buddy can give you ammo. Maybe you could even trade things like armor or in-game unlocks/currency. It should work in that players can go to a trade menu and view the offers for the trade. They then can agree or make a counter offer by asking for other items or offering new items. (Maybe like Borderlands). I think that allowing players to actively give and trade items would be a MAJOR addition to the game and foster even greater social interaction among roaming players who come across other players.