Iain Banks wrote this cool article about some basic aspects on his semi-galactic civilization, The Culture. Like Banks himself, I'd love to live there. Like he said, the idea was to make a Utopia which was about as good as he could imagine it within realistic standards for a human society. And he also said it was the driving engine for the whole series of books, which I find really interesting and cool. Most writers, moi included, sadly find it much easier to be driven by darker ideas.
Of course this is countered by the fact that to get narrative tension, most of the stories take place on the edges, where the peaceful culture meet less placid alien cultures.
I would love if the Culture would be added to Kindle Worlds, where fan fiction authors can get their stories selected, and monies earned are split between the author and the owner of the original world. It's a great idea. (Though so far, sadly, limited to US citizens. Payments and taxes issues, for sure.)
Of course in the case of the Culture, this might be a bit redundant. It has no recurring characters, and the stories tend to take place widely spaced out in time and space, and within the Culture and the book series, it has such fantastic variety of... well, anything, that one might as well make it all up oneself, simply inspired by Banks.