I mentioned in a topic as a joke that, just wait for the third generation P800 to come out and it would have a 3.2pix cam and a flash with a fuel cell battery.
Got a bit of feed back asking what one is. NEC has made a laptop run for 40 with one and one day we will have them in our phones.
but people asked for a link as I think they did not beleive me, so here it is
Some companies claim that they'll have phone fuel-cells coming to the market around the end of the year. Don't expect dramatic increases in life though (perhaps 3x) in these first generation cells. Also, remember that'll cost you more to refuel them (they use custom fuel canisters) than to charge your phone from a power outlet.