Here’s a nifty product from GP. The GP Charge AnyWay is a USB Battery Charger that is also a power bank.
It can charge AA and AAA rechargeable batteries. There is a MicroUSB port for charging the batteries and a USB port for charging other devices.
This is great for traveling. The GP Charge AnyWay is quite compact and you can use any USB hub to charge the rechargeable batteries.