LG Chem is on the ball when it comes to fuel cell technology. They have developed a fuel cell unit for user in notebooks that can power a 25W unit for up to 10 hours. The only problem is that it is an external unit so that makes yet another accessory that you would have to lug around with you:
Different from the concept announced by Taiwan-based Antig Technology at the CeBIT trade fair earlier this year and other companies before, this product works as an external power supply connected to a notebook through a DC-in jack, LG Chem explained. The device weighs less than 1kg, and one 200cc methanol cartridge is enough to power a 25W notebook for more than 10 hours, LG Chem said. The company expects that cartridges will be priced under US$1. The base unit price will be around US$500.
but think for a moment. How are you going to get through airport security with multiple 200cc vials of methanol? I wouldn't even try.