The Brixton currency

There is an old joke about a man stopping to get tank of gas, a doughnut and pack of smokes for about $14 dollars in Wheeling, West Virginia. With a big smile on his face, the station attendant hands him a $17 West Virginia dollar bill, telling him to keep the change. The Brixton currency, which circulates in neighborhoods of southwest London, is exchanged 1B=1P and only one of the alternatives to official money created lately, including the bit-coin, used in commerce mostly on the Internet. One can only wonder if these guys have heard the above joke?