Polywork is a clear winner in the area of community building. It's like a cross between LinkedIn and Facebook but with a much smart design, and a user-centric development approach.
I started using Polywork recently and was pleasantly surprised by the deep well of opportunities listed here. It was nice to see a site for someone like me -- I dont just have a job, i'm also on boards, i'm an investor, I want to participate in community projects. Polywork was great at helping surface interesting opportunities for active people looking to get involved and grow themselves across many dimensions.
