I've long thought that fuel cells in mobile phones were never going to happen. Yes, they pack a high energy density, but the idea of using a methanol-fuelled device by my head has never really appealed, especially given the ongoing risks of "normal" high-energy batteries spontaneously combusting.
I'd also been skeptical about the notion of taking cells with flammable contents on board aircraft. And yes, I know about less-flammable things like borohydrides, but given the hoo-ha of the last week about any liquids being taken on-board flights, I think we can finally lay this idea to rest. A pity, as it sounded kind of cool, but I think this is one area where practicality will get in the way.