Short Answer: Yes, Long Answer: Sooner than you might think.

As a follow up to a blog post I wrote many moons ago (that has got a lot of search traffic—thanks Google!) titled "Really, what's a Gigawatt" here's a post I just found over at Inhabitat.com that answer the question: Could the Entire World Really Run on Solar Power? Check out the infographic that goes along with it!

How's this for a mind-bender?

http://blog.makezine.com/archive/2010/07/using_squirrels_as_a_power_source_v.html

“I figured they could be put to work,” McHugh said. And that was the acorn that grew into his second career as a kinetic artist.