AA Batteries That Charge Via USB

I saw these USBCell AA batteries and got to thinking, how come more handsets don’t come with the USB cable built-in? I mean, how cool would it be for your phone to have a USB plug on a short 3″ lead that pulled out of your handset? You could easily plug it directly into any computer as a mass storage disk or to charge.

Obviously, you’d still need a wall charger to be in the package, but it could just be a USB extension cord, really, which plugged into the phone.

Makes you wonder what other little things could potentially be built into a handset, doesn’t it? What about that patent (I think it was for Sony Ericsson) to have the Bluetooth headset built into the phone? Why not put a solar panel on the whole back of a handset? Or a pop-out stand to prop the phone up for video viewing?

I wonder if someone in some lab somewhere has already tried this, or if they’ve even thought of it before?