If you’re really into grokking the evolution of social media sites, how communities develop and grow, and how tools evolve to effectively enable engagment, you should check out a very useful conversation happening over at DailyKos, where users are engaging in big dialog over the features and functionality that will define DK4.0. This is in-the-trenches product development with a de facto customer advisory board, and it’s incredibly enlightening to browse through some of the former "great ideas" the community is panning now, and the new suggestions they have for building a better community site.