Not all transactions based on something other than legal tender qualify as barter!
People keep talking about the resurgence of bartering within this weakened economy (I have yet to see it, but that's not surprising). But Instapundit just linked to an article with the headline "In tough economy, some turn to trading for items and services," saying that people are "responding to a tough economy with barter." The story discusses a system wherein people join a group and then earn "trade credits" by providing goods and/or services, and then these credits can be redeemed with other participating people or companies. Get a grip, people. Bartering is the direct swapping of one good or service for another. This isn't barter. This is scrip - an entirely different phenomenon.