gigantic aftermarket batteries that make our phones so fat they barely fit in our pockets. So there is this company, Lilliputian Power Systems, that is just starting to market a tiny, butane-powered fuel cell they call the Nectar that plugs into your cell phone (or whatever) through a USB port and supposedly charges it for up to two weeks. That's a lot better than an add-on battery. It looks expensive, although the power "pods" aren't too pricey at $19.99 for two. But wait a minute: Why aren't fuel cells, not internal combustion engines, the "range extenders" in plug-in hybrid cars? A decade back, fuel cells were going to revolutionize our power delivery and consumption systems. A cell phone charger is cute, but is that really all we can get fuel cells to do?