AC Propulsion has converted an xB into a fully electric car. Sure, it might cost 70K but it's still pretty cool.

http://www.autobloggreen.com/2006/12...-public-debut/

 

As much as i love the XB, i would rather buy a porsche, or a Z06 for that much $$.

 

Yea, that's true, but for cruising around, it's hard to beat the whole "no gas" thing.
The big part of this is that eventually, the technology behind electric car conversion will come down in cost.

At this point, it seems likely that electric cars will be commonplace in the next ten years or so. (hell, look how many people have converted their VW to biodiesel.)