Most of my gear is equipped with an USB connection e.g. my Suunto Ambit 2, my phone, my camera or my Petzl Nao headlamp. But hey, I always run out of battery after 2 or 3 days and there is no USB connection in the forrest in order to charge my devices.
I found a solution which could extend the usage of your electronic gear for a couple of days.
The Anker Astro3E features high capacity for a low price. It also offers multiple sockets, weights 240 grams and has the size of a mobile phone.
It comes with plenty of connectors and you can even charge your iPad with it. With the battery you can charge 6 times your phone and you can even charge 2 devices at once (since it has 2 USB sockets with 3100 mA / h on each socket). There are also 4 blue lights on the front of the device which indicates the capacity of the battery. Charging of the battery via USB takes up to 8 hours on your PC and 15 hours on your laptop. The case which is included in the package seems to be useful too. It is mashed and feels quite soft – should protect the battery in case you drop it.
Here you can see how the Anker Astro3E charges my Suunto Ambit 2.