Steve,
Make magazine ran an article on converting your own car to electricity in Vol 5. It looked doable, even to a non-electrician like myself. You can subscribe to the digital edition now and get the archives for free.
http://www.makezine.com (though as I type this, something seems to be not quite right with their server).
yvan, all carbon fuels put CO2 into the atmosphere, but growing plants for biofuels takes it out again. That's how the energy is stored. Remember, plants make sugars as a food source by using the energy in sunlight to break up CO2 and recombine it, ready to be combined again with oxygen to release the energy stored in the sugar. Plant sugars are nature's battery for solar energy. Alcohol fuels (including ethanol) derived from plant sugars harnesses yeast to convert the sugar to a form human machinery can more readily use for energy-- though I still have a problem with converting sugar/food into fuel. However, plants also convert CO2 into cellulose for structural purposes, and that can also be converted to human-usable energy, either by burning, as with wood, or by fermenting to methanol. Biodiesel uses fats created by plants to store energy, which again use CO2 from the atmosphere.
The remaining problems are efficiency (do we design engines to use as much as possible of the solar energy stored in the biofuels?) and clean burn, which are related issues. Alcohol burning at perfect efficiency should produce only water vapor and CO2 - no more CO2 than was removed from the atmosphere to produce the alcohol in the first place. But incomplete/inefficient burn can result in CO (carbon monoxide, a poison), NO (nitrous oxide), O3 (ozone), and soot (carbon particulates). All of these are health hazards to most animal life.
Sorry for the lecture-- I guess I've spent too much time thinking about this lately....