Biodiesels and hybrids are great. If only VW would make a hybrid with one of their high-efficiency diesels... It would get 60-80 mpg by my estimations. Maybe more. Then run biodiesel in it. Awesome.
But even all of this is just a temporary solution... It's partially based on non-renewable resources and still pollutes.
Solar, wind and hydro power charging hydrogen fuel-cells is the real eventual solution.