So, how often does your phone or other device run out of charge?
These days, charging stations are showing up at airports, in convention centers and in many malls. Now Boston has introduced them in public parks...and in a very environmentally-friendly way. The "Soofa" park benches will provide solar charging for your phone and limited-access wifi to allow you to check the weather and air quality. The idea will, no doubt, spread.
There are all sorts of other ways to recharge your phone if away from mains (or car) power.
Some of my friends, for example, now carry extended battery packs that can double, triple, or quadruple the battery life of a phone. Solar chargers are also common, and I've considered getting a hand crank one myself. You can also get wind chargers, although they look a bit goofy. If there's not enough wind, just hook them to your bike handlebars.
For campers, you can now get a camp stove that charges your phone. Put wood in it, start the fire, and some of the heat gets turned into electricity.
So...yeah. And in the future, maybe those charging stations will charge your phone wirelessly. Maybe you won't even need to do anything other than be within range and you'll get a top up...
Then again, maybe having your phone run out of juice every so often isn't such a bad thing in an over-connected world.