Sometimes, an idea is just so simple and yet so cool that you just end up shouting "that’s BRILLIANT" across the room. The USBCELL is exactly such an idea.
The principle is simple: a standard battery of the kind that are used in just about everything, but with a flip-off top that exposes a USB connector, so you can charge it up from anything that has a USB port capable of carrying power. Batteries run out at work? No problem – just plug them into a USB port on your computer and away you go. Got a full laptop battery on a trip? Plug these in and get more charge.
I haven’t tested them yet, and I’m guessing that the space used by the USB plug means you’ll lose some battery hours. Also, the price looks a little high, at two AA’s for £12.99. But for the extra convenience, they look brilliant. I’ll definitely be buying some.