http://news.bbc.co.uk/1/hi/sci/tech/8556656.stm

This is potentially interesting.

It's just a shame you can't recharge them.

Fuel cells are potentially far more efficient than rechargeable batteries.

Consider a car. You can either recharge a battery electrically using power currently produced and delivered at around 20% efficiency which may take several hours, or you can fill it up with a primary fuel as conveniently as a petrol car.

However, using RDX as the fuel does sound a little too exciting. You sure as hell would not be allowed such a high explosive on a plane to run your laptop, and I'd be a little worried driving around with enough Semtex under my bum to send me to the moon in atoms.

http://en.wikipedia.org/wiki/RDX

Of course, high energy density power sources will necessarily be a little dangerous. Lots of power contained in a small place will always carry a risk.

Isn't that an explosive? RDX I think.

Bouncing fuel cells anyone?

[Edit] That'll be a D'Oh! then

There was a laptop version that could be recharged with lighter fluid if I remember rightly.

I remember nanotube batteries being in the news last year, but I forget the details.

There are DMFC catalytic fuel cell chargers available right now which run on methanol, but I don't think you're allowed them on planes either:

http://www.toshiba.co.jp/about/press/2009_10/pr2201.htm