If air travel has much of a chance of surviving into a sustainable post-oil future, it’s going to have to become a lot more energy efficient. And while I love jet aircraft as much as the next world traveler, I recognize that they burn a hell of a lot of fuel. But perhaps the answer lies in something a lot simpler. A century ago, airships beat airplanes hands down in terms of range and cargo capacity, but were held back by the limitations of their materials. Today though, we have far lighter, stronger and longer-lasting materials and a much greater knowledge of aeronautical science. Some groups are even trying to use them to launch space shuttles. What possibilities could lie ahead in terms of solar balloons, bicycle power, sails or other zero-fuel technologies. And the best thing is, since so much of this technology hasn’t changed much basically in almost a century, it can be within the reach of small groups of inventors.

The Airships (parts 1, 2, 3, and 4) is a long but brilliant series about the history of big airship travel, with a lot of focus on the geopolitical reasons they never caught on (Germany wasn’t a very popular country for that era).

Here’s a guy who crossed the English Channel on a bike-powered blimp.

Not technically related, but also amazingly cool: Floating Balloon Wind Generators – a brilliant new innovation in wind turbine technology.

And finally, here’s a series of videos (unfortunately so-far unfinished), about a bunch of British students building a bicycle-powered airship for a class project, and it gives you a sense of how easy this kind of thing could really be. Who wouldn’t love to take a cruise off the escarpment in one of these things?