I’m no survival expert, so this is about keeping your electronics (both practical and fun) running if you lose electricity for an extended period of time.
Practical
First of all, you need a way to capture the power of the sun. I have a Socosche solar charger/battery. There are many different solar chargers on the market. I like the Scosche one even though it doesn’t produce a lot of current or have a large battery, because it is compact and feels sturdy.
To distribute the charge, I use a Sanyo USB charger. As of 4/2/13, this charger may have been discontinued, and I don’t see any good alternatives. To go with your USB battery charger, pick up some eneloop AA and AAA batteries. These are a they should stil have some charge when you need them.
Now you can power most devices. I recommend having an LED headlamp and/or an LED flashlight. For headlamps, I like pretty much anything by . Most if not all of their headlamps use 3 AAA batteries. For an LED flashlight, I like Streamlight MicroStream 1xAA LED Flashlight or Streamlight 2xAAA LED Pen Flashlight. Both are nice an bright, last a long time, and feel well built.
Beyond these items, a portable radio that takes AA or AAA batteries would probably be good.
Fun
In case the solar charger/battery doesn’t store enough juice, pick up AA to USB charger/battery adapter. This will all you to use those AA eneloops you charged during the day to power your gadgets at night.
Make sure you have all the USB cords and adapters necessary. It can be a pain keeping track of the little pieces, but my Universal Charging kit consists of: