Treehugger has a slideshow of the best and worst ideas in sustainable transportation from 2009. But, instead of debating the varying merits of this or that electric car, they've left cars out entirely, in favor of planes, trains, bikes and boats. Bikes get the most play here, and there are some innovative ideas—like cargo bikes and bike highways. Treehugger is mostly talking about their use in places like Copenhagen, but I love how Minneapolis' system of limited-access bike trails makes bike travel and commuting faster, easier and more enjoyable. (They're even plowed in winter!)
I do with the slideshow had focused less on the bikes, and more on mass transit and shipping. Mass transportation is a key component in just about every plan for lowering greenhouse gas emissions, but it doesn't get nearly as much attention as every random attempt to revamp the personal car. There is, however, some interesting stuff about high-speed trains and early developments in alternative-fuel aviation.
Maggie Koerth-Baker is the science editor at BoingBoing.net. She writes a monthly column for The New York Times Magazine and is the author of Before the Lights Go Out, a book about electricity, infrastructure, and the future of energy. You can find Maggie on Twitter and Facebook.