Living in San Diego, you spend a lot of time at the beach. There, it’s a tragedy to have no outlets to recharge things, while you have a lot of sun available. Ideally, you would use a solar charger to recharge all your devices while they are being used.
There are lots of chargers on the market. Solio makes very popular ones, but they are by far not the only vendor. Basically, all of them in one way or the other allow you to connect a variety of devices to a solar panel that outputs the correct power (voltage).
When buying a charger, you should look mainly for one thing: that the output is USB. Dedicated plugs are nice, but ultimately you’ll end up connecting most devices via USB, so something that requires an adapter to get to USB requires you to carry something extra (Solio, for instance, mysteriously has output that looks like USB, but isn’t. You need an adapter to translate to USB, which is really stupid. I assume it’s done to have something else to make you lose and buy.
The devices, though, are a little more challenging, since there is more than one thing you have to look at.
First, the device has to be able to live with the power output of a solar charger. That’s not a given. For instance, despite having a mini-USB connector, my MP3 player sunglasses completely refuse to work with the Solio charger. They just don’t charge at all, ever.
Second, the device has to be able to continue functioning while it is being charged. It doesn’t do you any good if the device stops functioning while charging. My Blackberry 8830, for instance, refused to connect while being charged (as long as it was below a certain charge).
Finally, solar charges typically output only small amounts of power. That means that if you have a power hog with you, the solar charger may just not be able to fuel it much. My Nokia N900, for instance, burns through power so fast that I’d rather not rely on the charge and instead carry a spare battery.
(Final gripe: with all the crap that went into the N900, couldn’t they have given it a battery twice the size? The replacement batteries weigh nothing, and the original battery runs out of juice scary fast.)