Been around for 50 years but not of any great use. a 25lb battery capable of putting out at best a milliwatt or two. So to get any usable power out of it you can hook it to a capacitor or battery for peak loads but you still need to average less than a milliwatt so the capacitor can stay charged.
Slashdot has some good comments on the whole issue
Hmm, after reading much of the wikipedia and slashdot articles, along with taking a grain of salt, lol...It seems that we are still a ways off from having this technology in consumer vehicles. More than likely we'll see it in lower power consumption things like laptops, cell phone, watches, etc.
Good reading though, thanks for the posts, Coyote.