[Kristine1975]

>I expect/hope we'll one day discover/invent a source of energy that is nearly-free, nearly-infinite, and nearly-zero-maintenance.

The sun? :-)

[paulmd]

Twenty billion years isn't forever. In fact, I think there's a story about that. ;)

http://multivax.com/last_question.html

[wlievens]

Fits in a truck? Check!