Via ohtheplaceswewillknow:

Alex Steffen gave a nifty TED talk about sustainable urban spaces. He touched on a lot of important notions such as the need for energy-efficient smart buildings, or that dense cities are more sustainable than sprawl because people walk or bike instead of drive (obviously). Favorite part:

"Studies say that people are surrounded by places that make them feel at home, often give up their cars altogether…People are saying that it's moving from the idea of the 'dream home' to the 'dream neighborhood.'"

Thankfully he stops short of promoting hyperdense skyscraper culture - this makes it seem like the ideal city would be made up of densely clustered neighborhoods, each carefully tailored to their demographic. (Whatup Jane Jacobs?) 

This comprehensive article on Treehugger seconds the notion:

Kaid Benfield:

 For our cities and towns to function as successful people habitat, they must be communities where people want to live, work and play. We must make them great, but always within a decidedly urban, nonsprawling form

James Kuntsler: 

I don't think there's any question that we have to return to traditional ways of occupying the landscape: walkable cities, towns, and villages, located on waterways and, if we are fortunate, connected by rail lines. These urban places will exist on a much smaller scale than what is familiar to us now, built on a much finer grain. They will have to be connected to farming and food-growing places. A return to human scale will surely lead to a restored regard for artistry in building, since the streetscape will be experienced at walking speed.

Photo by TED.