Pluggable Hybrid Video
Pluggable hybrids can be plugged in to the electrical grid, or other source of electricity. Electrical energy is currently less expensive per unit of energy, than petroleum based fuels. As time goes by, electricity should become more available and de-centralised, while petroleum will probably trend more expensive, over time.
Battery technology is lagging far behind the needs of modern travelers. Electric vehicles are severely limited in their travel range, due to the miniscule amount of energy storage that even very large and heavy battery banks can contain.
Current battery storage is a joke. Fuel cell technology, on the other hand, promises to advance more quickly in the near to intermediate term than battery technology. Fuel cells that run on biofuels would run fairly clean.
Pluggable automobiles that combine fuel cells running on biofuel, with state of the art electrical storage batteries, may be the best near to middle term approach to personal transportation. Ultracapacitors may by some miracle become good enough in energy density to replace storage batteries, but that would require significant advances in nanotechnology. By that time, integrated molecular manufacturing will probably probably blur the distinctions between the ultracapacitor and the storage batter. Fuel cells will also become far better, and closer to the high performance in both energy and power densities that typify the internal combustion engine--while maintaining a cleaner and more efficient operation.