I love how science fiction is becoming a reality. In a lot of sci-fi stories, there is a term for this. It's called wetware.
Looks like even before commercial pocketable fuels cells are available, they might be surpassed by partially organic cells. Of course the downside is that you'd have to water them once every 3 weeks, ensure they get a good 3hrs of morning sun and partial shade from noon onwards, fertilize regularly and weed and mow them. /ubbthreads/images/graemlins/grin.gif
I can just imagine it now:
"Is that a garden in your pocket or are you just happy to see me?"
and
"Are you still using the Spinach 2020? I've upgraded to the Kale series 4000!"