I run a photography rental studio on the side, where people shoot everything from fashion look-books to stock photography to images for toy packaging. I've spent eight years kitting the studio out with every basic piece of equipment a crew would need to conduct a shoot. But the number one thing that everyone asks for is not a particular type of strobe, or stand, or backdrop: It's a cell phone charging cable.
After the strobes, the iPhone charger is probably the most popularly-used piece of equipment in there. I have no idea why this is; you'd think everyone would just plug their cell phones in every night, but my observation is that many people don't and are constantly running out of juice.
An idea recently chosen on Quirky, but yet-to-be-developed, may provide the answer. It is not an exact fit to this problem, but could be: The idea is for a bracelet that is actually a wearable USB syncing cable. If this were modified with prongs so that one end went into your phone and the other into a proper socket, I think it would be huge.
A fair bit of technical trickery would be required to wedge a bulky adapter into a slim bracelet, but imagine the convenience. If your phone ran out of juice and all you had to do was find a socket and whip your bracelet off, I think a lot of people's lives might be made easier.
Then again, the success of this theoretical object is predicated on people remembering to put it on—and remembering to take it with them. Anyone wanna take a guess on the number one object left behind in my studio? It's not CF cards, laptop cables, or merchandise: It's cell phone chargers, left plugged into the wall in a forgotten corner (occasionally with the phone still dangling from it).
What do you think, would a phone-charging bracelet do the trick?