This is a great TED talk about how sustainability - through smart design - can improve quality of life, and help more people satisfy their basic needs more effectively, while processing and cycling resources at a sustainable rate.
The concept of the "8 House" was particularly striking to me. A few years ago, I mocked up this conceptual slide of what a mixed-use development could look like that would have all of the elements of primary production, industry, work, life and play. The core pattern was a figure 8 with a closed-loop industrial ecology system interacting with a mixed-use residential/commercial system; all walkable with minimal need for imports and excess capacity to export efficiently by rail:
Obviously, this is highly over-simplified and conceptual, but it's exciting to see how design can maximize daylight and solar gain, balance public and private green-space for the community, and easily engage in both urban and rural / natural environments without a vehicle. It's a inspiring to see that something moving in this direction already exists.