I recently picked up a surplus battery-powered motor assist for a bicycle, and it's a lot of fun. Due to lower power you have to start peddling to 3mph and then it can run the bike for 10 miles at 10mph (for normal weight people, not me.)
All-electric cars didn't do well in the market in part because people were scared of their limited range, slow charging and and high cost, and the annoyance of plugging them in. They love hybrids because they don't have the range problem. Some folks are promoting plug-in hybrids, which are hybrids with lots of batteries. You can and should charge them from the grid, but you don't have to, so your range is the same as a gas car (or better) and on most trips you are much more efficient.
But perhaps cars are the wrong target. Electric bikes are heavy and a little more unstable when slow or being walked, and get really bad if you put enough batteries on them to go 20 or 30 miles. But trikes on the other hand are stable and you can load a lot more batteries onto them for serious range. And electric trikes are wicked efficient, in terms of cost (and fuel burned) per mile of travel. Orders of magnitude ahead of hybrid cars.
And all this is quite cheap to make if done in quantity. If our cities made more bike paths and bike lanes these trikes could become a major commute form, especially in California with its assured good weather. Yes, it's not perfect -- you have to recycle the batteries, and you do have rain to worry about, and the speed is definitely lower. But for shopping trips, neighbourhood trips and short commutes it seems a giant win.