Dynamic carpooling- I've brought this up before, whether here or elsewhere. Now I see a description of it on Wikipedia. This is the social side of a combined social/technical solution to optimizing transportation efficiency. If you have a long commute it would really pay off. Just the other day I heard Daniel Sperling bring it up during his interview on NPR.
I think there is a misconception about the right path to a more efficient or globally responsible way of life. People tend to conceive this as a problem that requires a single solution. Of course, it requires many different solutions and approaches to the problem. I think the reason for this is that few people are willing to change their behaviors and accustomed way of living, and accordingly, if they wish to reduce human caused pollution, they hope to achieve this almost exclusively through technological innovations that make their consumerables less polluting. When it comes to vehicles, these are the people who see solar-electric and fuel cell technology as the answer to a healthier planet. I think this is very narrow thinking. Before I am accused of being a Luddite, let me state for the record that I would be the last person to say we do not need to develop better technological solutions and find ways to affordably mass produce them to get them into the hands of consumers. However, if we remove resistance to social change and our engrained behavior patterns, we do not need any technical advances to acheive the goal of sustainability. I know, it is easy to say, but it is also easy to forget. Sustainability is more a behavioral problem than a technological one. Answers that address our way of living can provide solutions right now. Technology will provide us with new possibilities, but let's not sacrifice our past in the race for the future. Let's do what we are already able to do right now.
A few more misconceptions I see:
Few people seem to know what waste really is. Waste is not waste if it can be used as a resource or fuel at the next step down the chain. Just because it isn't used right now doesn't mean it won't be put to use later or by someone or something else. Waste is better defined by it's social and environmental costs, which need to be understood first. Before we can understand efficiency or recycling we need to know more about waste.
More is not always better. This assumption often goes unnoticed. There is a futurist periodical called "Infinite Energy"- maybe I should coin the term energy lust to describe this, because I have no idea what someone would do with infinite energy were they to actually get it.