SAN FRANCISCO - EDITOR'S NOTE -- One in a series of stories assessing how last fall's financial meltdown and the Great Recession have changed our lives.

Our economy sure could use the Next Big Thing. Something on the scale of railroads, automobiles or the Internet -- the kind of breakthrough that emerges every so often and builds industries, generates jobs and mints fortunes.

Silicon Valley investors are pointing to something called cleantech -- alternative energy, more efficient power distribution and new ways to store electricity, all with minimal impact to the environment -- as a candidate for the next boom.

Where's the next boom industry? Maybe 'cleantech'