Fuel cells are often said to be the next leap in power supplies for cars, busses, and other generally large consumers of power, but that is not where most consumers will first use a fuel cell. Methanol-based fuel cells are being used in MP3 players and other handheld electronics already. Using hydrogen, in a very controlled state, the batteries can last over 60 hours.
The catch is that these new batteries are expensive, but with more advanced consumer electronics coming out that require more juice, it seems that the time is rife for these longer-lasting and reusable batteries.