The Turing Test by Chris Beckett
Several of the stories feature a future in which the real world has a virtual world superimposed on it in an effort to conserve resources. There's a hierarchy and a kind of distrustful discrimination between the two populations of real people and virtual people. The virtual people can earn themselves higher resolution and those at the bottom of the virtual social scale are low res with moon faces, lines for mouths and dots for eyes. It's clearly a very well worked out place and I can imagine Chris Beckett developing these into a novel.
My favourite stories are those that involved a more anthropological element. There was a world in which the women lived in walled cities and the men marauded around outside, having to face an initiation test to mate with the fertile women in a tower; then in the last story ('The Marriage of Sky and Sea') a man from space lands in a planet with a large moon that pulls not just the sea but the ground too. It has a superb fairy-tale feel and parts of it are beautifully written too.