Expansys have just started selling the IGO PowerXtender Battery charger.  I use all the IGO chargers for mobile devices and also my laptop.   Why... well I can carry just one charger and charge all my devices from one unit!

With this battery operated charger you can use the same tips for charging your devices from 4 x AA batteries!

Mobility Electronics iGo powerXtender Battery Operated Charger | eXpansys Code: 142648

You can buy it from Expansys from HERE