Players can always drop items for you, but not alot do so, and its somewhat wordy to always type out "Hey can someone buy me a xyz?" Until we get integrated voice chat, that is 
What would be cool would be if you could mark items in the shop that you want.
And then when someone hovers over your char, it could show a little bit at the bottom like "Wants: boots of speed, teleport scroll" , and in the shop, it could pop up when you hover over an item: "Wanted by players: Frogboy, CosMoe".
Generous players could then buy said item for a player and the player can go to the shop and pick it up. The player would get a little msg like "CosMoe has bought you: Boots of Speed".
Might give a little depth to allow strong players to easily directly assist teammates. And if its build into the game, it would be more encouraged than simply having to drop items.
Maybe this is something that can be done with mods even?