USBCell: AA USB Rechargable Batteries (Link)

This revolutionary rechargeable battery can charge from any USB port without the need for any recharging devices, cradles or cables. Simply pop the lid to reveal a built in connector and charger, plug into any powered USB port on your desktop, laptop, keyboard or games console, to charge the battery.

USBCell can be used exactly like a normal battery meaning there is now no need to purchase huge packs of alkaline batteries, or invest in or carry a clunky charger. Billions of USB ports are readily available in homes and workplaces around the world meaning you never need to run out of power and making the USBCELL extremely cost-effective and convenient for all battery-powered devices. Currently available in the AA format, the USBCELL will shortly comprise a full range of standard formats, phone and camera batteries.

USBCell by Moixa Energy was launched September 19th and already received some good reviewes like the one from TrustedReviews:

"I was frankly, amazed how long the batteries lasted and I was snapping pictures for what seemed like hours. After a while the camera finally flashed up the battery flat icon and shut down. I placed the Compact Flash card inside my card reader and was surprised to find that I’d taken a simply astonishing 563 pictures ... To compare I then tried a set of Duracell Alkaline batteries in the camera, only to find that they weren’t even strong enough to take more than a few pictures. It seems you need Duracall Plus or Ultra M3’s to deliver the amperage that a high power device such as a digital camera needs. This makes the USB Cells seems all the more impressive."

It's currently available in the UK for £12.99 (US $25.78) for 2-cell pack.

Read Also:
USBCell (Product Page)
Moixa USBCell AA Batteries (TrustedReviews)
USBCELL batteries feature built-in USB plug (Engadget)