The Jerrycan has some interesting history, a design that has rarely been bettered and much copied. Useful for a 'Blitzkrieg' Bug out Vehicles or BBOV.

https://en.wikipedia.org/wiki/Jerrycan

For example putting 5 20Litre Jerrycans of Diesel into the back of a modern Citroen DS3 Diesel @ 60+ mpg (US) combined would give around an extra 1500-1600 miles range.

Looking at some of the Storm Sandy photos of folks standing in line, it doesn't look like the Jerrycan isn't particularly popular/available in the USA.