Germophobes and OCDers may want to stop reading now, or at least seriously consider only continuing with a bottle of Purell on hand—for today, we're talking about bacteria, those squirmy no-see-'ems that densely cover just about every surface imaginable here on Earth, including your own skin. However much hypochondriacal hatred the mention of them can bring about, as with other quasi-oxymorons like "good cholesterol," we'd be in a lot of trouble if it weren't for bacteria. No higher order life would exist without them; they keep us alive and support our economy, and, frankly, most would be happy to go about their business having nothing to do with us. There are only a relative few that keep us washing our hands constantly for fear of illness. It is this great ubiquity and diversity that allow scientists to put both natural and modified bacteria to work in a wide range of beneficial modern technologies.