Could you clarify this idea a bit more? Are you thinking of using this multimedia database in your pocket primarily as a training aid or reference--something you can review when you're on the bus or otherwise have free time? Or are you thinking of this primarily as something you'd consult during an actual emergency?

If it is the latter situation, then I think that I would be very wary of using up my phone's battery in any situation where the power is down and I'm not sure when I can recharge the battery. I think I would be more apt to use this multimedia library idea during an emergency if it was something separate from my phone, like a PDA, so that running down the batteries doesn't also affect my communications ability.

Anyway, just wasn't quite clear on the concept.