This trade plugin will be a safe and easy way to trade. It could have commands like /trade "username" /trade accept /trade reject (Player has to wait a certain amount of time to send another invite.) Spout will come in here.... Both players will see a chest on there screen title at the top "trade" you put what you want to trade on your side and they put what they want to trade on there side. Then you hit "T" to accept the trade. This would be a good plugin to prevent scamming on servers. Two players could just go into a non PvP area and trade there items.
How would you see what they trade? You wouldnt be able to share a chest screen (not that i know of) so even if you could put items in the chest trade window, you wont know what you're getting till after you trade, which seems like more of a chance to scam.
Actually this is quite possible to do and I would love to see it implemented. http://forums.bukkit.org/threads/fun-connectfour-v0-3-2-now-with-tic-tac-toe-1060.29165/
You need to browse the forums more. Done and Done. http://forums.bukkit.org/threads/econ-spouttrade-v1-0-trade-items-using-an-in-game-gui-1060.32432/ Good job.