DME is at the bottom:

http://www.alternatefuelsworld.com/fossil-fuels.html

Also, there was a diary at Kos on Sunday on cellulose alcohol from the willow-poplar-aspen complex:

http://www.dailykos.com/story/2007/1/14/11436/7393

I'm betting my piggy bank on cellulose ethanol;perhaps it could even be a feed-stock for DME.

If history is any guide to the future, I may be right:

http://en.wikipedia.org/wiki/Timeline_of_alcohol_fuel

Or not.

"When the abyss stares at me, it wets its pants." Brian Hopkins