Sometimes the smartest ideas are the most obvious ones. Add to this list the Belkin Micro Auto Charger that turns your car lighter socket in to a USB charger. Coming soon for the princely sum of $15
H/T to Gadget Lab from Wired.com
I've had one of these for years Steve! Essential for charging MP3 player, FM transmitter, phones etc when travelling. Gets used a lot on our camping trips...
These are much better and more flexible and made in the UK https://powertraveller.com/iwantsome/primatepower/000193/
Dave
not so sure dave...I have something similar but just want to simplicity of the Belkin that I can leave in the car and don't need all the connectors