The Washington Post’s “Monopoly money? Nope, just local currency” discusses Anacostia Hours (around since 2006) and other local currencies:

Local or alternative currencies are almost as old as trade itself, but the movement has found new life amid the global financial crisis, as parallel economies outside the traditional monetary system have emerged in countries such as Spain, Mexico and Brazil. These systems are flourishing because the unemployed can either trade skills for local currency or swap their time for other services.

Read more here.