Bruce Sterling's Distractions
Via /., in a post about social reputation and whuffie : 'Distractions' is set at the earliest cycle of a post-scarcity future and includes, almost as a throwaway subplot, a culture of ex blue-collar workers who were entirely marginalized because they had no skills of any value. However groups of them did have machinery which could turn any vegetation into edible food so they didn't have to starve. Also they could make things, provide entertainment or could do manual labor in exchange for anything else they needed. These groups travelled about, living in tents and other temporary housing, existing entirely outside the 'real' economy. In fact they had their own economy, built using a computer mediated status system, which determined each individual's worth and clout.