Valve has announced a new feature for Steam, whereby players will be able to exert more control over the process of trading.
Now players can propose both sides of the deal, selecting that which they wish to trade, as well as identifying that which they'd like to receive. Friends will be notified of the offer when they next log in, and can accept or refuse it, and players no longer need to be online at the same time as each other for a deal to go down, and trades can be sent and received using a web browser.