Diesel fuel produced by genetically-engineered bugs.Several Silicon Valley companies are already genetically altering microbes and small organisms--bugs, so to speak--so that they produce something for nothing. The something? How about petroleum products. The nothing? How about agricultural waste--wood chips or straw or other biomass. The organisms eat the waste products and excrete crude oil. “Ten years ago I could never have imagined I’d be doing this,” says Greg Pal, 33, a former software executive, as he squints into the late afternoon Californian sun. “I mean, this is essentially agriculture, right? But the people I talk to – especially the ones...