Apparently the brainiacs at Brown University are talking about a new
hybrid battery/capacitor technology that they got working in the lab.
It's quite interesting, as they expect that it eventually will allow very fast recharge cycles and high power loads, from not much bulk.
Teaser quote: "
It had twice the storage capacity of an electric double-layer capacitor. And it delivered more than 100 times the power of a standard alkaline battery.
<snip>
In width and height, it is smaller than an iPod Nano. And it’s thinner, about as slim as an overhead transparency."