Will the high price of oil makes airships a viable alternative? (mentioned in passing in the following article)
"Perhaps the most unlikely alternative to emerge in recent months is the rebirth of the dirigible or airship, as companies have already been unveiling new designs for niche tourist trips and transporting cargo." --The New Republic
http://www.tnr.com/politics/story.html?id=78260c55-a850-478f-9ffd-b8023fd89459