Honestly, I've had some good ideas in my day (the magnafinder…hello?!) but I'm kicking myself for not coming up with this first. Energizer has a new flashlight that works with any batteries you happen to have handy. AA? Yep. C? Yep. D? You bet. They've already got a couple trucks loaded up & headed out to help with the hurricane relief.
Now, how long do you think it'll be before someone takes this technology and implements it in…oh, I don't know…"back massagers"? (No! Wait! No one else read that! I'm going to invent it and be richer than Richie Rich!)