Before the comments ensue about it not being cost effective - you're right, it isn't. $10K+ in addition to the donor car is hard to swallow, unless your reasons go beyond saving money. If it's about saving the ozone, the air, the daisies and the baby seals, or simply alleviating your own conscience, this is one way to do it. The guys at Pioneer Conversions thankfully seem to be willing to work on other models besides the plastic domestics, so you won't have to deal with the amenity trade-offs in some hybrids or electric cars. They don't try to sell it as a money-saver either, so they appear to be honest eco-mentalists. Interestingly, they are able to convert a car to electric with an automatic transmission, something I haven't heard of before in a conversion. Follow the yellow brick 'Read' link to see their homepage.
[Source: JD Electric Vehicles Inc. -- Thanks for the tip, Sean!]