AA batteries aren’t going away anytime soon.  You can thank digital cameras, a variety of toys, and Xbox 360 controllers for that.  However, there are probably now more USB powered gadgets than their are standard battery powered toys on the market today.  Making sure you’ve got a back up battery for each respective type can be a hair pulling experience.  

Enter the Continuance battery concept.  The form factor is that of a AA battery, allowing you to power your compatible gadgets.  On the side, though, is a USB port, which presumably allows you to rejuice them and power up gadgets that only take a USB plug, such as the iPhone or any other smartphone on the market.  You’ll inevitably need a number of them on hand since their mAh capacity should be rather limited, but 4-8 should probably suffice in most instance.

Again, this is a concept only, but they’ve got our vote to move ahead with production.  We’re thinking Costco would be a good retail venue.