If you shoot tethered like I do, I bet you'll understand right away why these babies are so important. I recently had to send a D2x off to Nikon to have the usb connector in the camera replaced and the $400.00 spent for that would have bought alot of these one dollar wonders.

You'll find them at Walmart or similar in the camping department. I got the two you see above in a single pack for a little over a buck. Simply tie your USB cable around one of them and secure with gaffers tape leaving a little slack as shown. Hook the other through your strap loop and you're good to go. They disconnect and reconnect pretty much one handed and you'll keep your cameras usb (or firewire) connector safe, sound and fitting snug.