Ive had the bad luck of tripping over the USB cable while we are doing a shoot tethered to a laptop. Luckily I had an Austrian father that drilled into me to plan for a worst case scenario. How did I prevent a cataclysmic disaster from our gear? How do I do it on the cheap? Does it prevent wrinkles? I'll tell you! Basically I try create as many soft failure points as possible form the camera to the laptop. What do I mean by soft failure points? These are parts along the cable that can pull out or take some sort of jolt without affecting the rest of the cable.
I use one of the plastic covered wires you get with every pice of electronic equipment to hold cables together. Loop that around the mini USB cable side a few times so that it is tight enough to cause some friction if it does get yanked. Test it out by giving the cable a pull. It should be about halfway between completely free and not moving. If an accident happens, the friction between the cable and wire increases so it will still be pretty tight.
Connect that to the camera's strap buckle leaving a good length of slack from the mini USB to the camera. If that part of the cable is yanked then the friction will slow it down and the slack will prevent the mini USB port from being damaged.
Tied off but easy to undo.
Last point is to secure the laptop end to something so your shiny new Laptop does not go flying. Good old duck tape is an option but not the best. If you have enough slack it is far better to loop it around a table leg or something else thats immovable.