The Kodak KS100-C solar charger accepts two AA NiMH batteries, and can also charge a variety of other devices including digital cameras, so long as they are compatible with USB charging. In addition to its photovoltaic cell for charging from sunlight, the KS100-C charger also has a USB input allowing it to draw charge from an attached device such as a laptop to recharge another device's batteries.
The KS100-C includes two AA NiMH rechargeable batteries in the product bundle, and provides a method of charging devices in the field and away from power outlets - albeit rather slowly. Charge time is rated at 14 hours when drawing power from a computer's USB port, and a whopping 28 hours when using the solar cell as a power source. While it isn't clearly stated, these times are presumably valid when charging the bundled AA batteries (as charge time for other devices would depend on their battery capacity). In the case of the solar charging function, charge time will also vary widely depending on sunlight intensity.
Japanese speakers can find more details on Kodak's website.