I think it would be cool if instead of just dropping items on the ground for players to pick up, they could scroll over each other and select "trade". If both players select trade then a transparent-ish interface will pop up for both players and then "Player 1" would drag his M4 into "slot 1" of the interface, "player 2" would then drag the items hes willing to trade, say a grenade, into "Slot 1" of his section of the interface and select "accept trade". "Player 1" would then click "accept trade" and an animation would play and both players would now have traded. To keep them safe the interface would instantly go away if either player moves, takes damage, attempts to draw a weapon, or selects "cancel". If the interface is cancelled due to any reason listed above, both "player 1" and "player 2" must wait a few seconds to equip an item in their hands, this prevents players from abusing the interface to kill someone. This whole trade interface idea could also be dumbed down where each player scroll over each other, selects trade, and whatever item they have in their hand is then traded. You could also implement a "Give option" too.