
I remember on greatlakes there was this guild of trustworthy merchants that used to put on an auction once a week or every two weeks that players would all gather and attend to bid on items.
This is how it worked.
You gave your item to the owner of the guild/auction, in turn he would hold onto it and have an auction for the item in his tower on that date. They kept a small % I think it was 5-10%.
You could set an amount that the item had to reach to in order for it to sell.
At the end of the auction, the players would meet with the seller and he would sell the item to them in a trade.
Once that is done, he would contact you and give you your money for the item.
I think this would be a really good idea to get people involved with trading and trading on the forums can sometimes be a hassle and not many people even go on them.
The main question is: who is trustworthy enough to be intrusted with your items.