The interface cable that you insert one end into your camera and the other end into your computer's USB port is usually just 6 feet long. Wow, a very short "ball and chain." My Canon 7D and my new Canon EOS 5D Mark III 22.3 MP Full Frame CMOS with 1080p Full-HD Video Mode Digital SLR Camera (Body) (Canon 5D Mark iii, Mark 3) is also just 6 feet in length. Sure, that is adequate when transferring and uploading images from your camera to your computer. (I hope you don't do this and use a card reader instead.) Adequate, but not good enough. Onwards. Upwards!!! Yes!!!
What about shooting tethered? If you've shot tethered you will certainly know the limitations of having just a 6 foot cable. If you walk just one half step too far, yank, and out goes one end of the cable. When you are shooting tethered with Adobe Photoshop Lightroom 4 Upgrade Lightroom 4 (or Lightroom 3) you know that you have to restart the program because the cable came out. Time consuming and potentially embarrassing, especially in front of a model, let alone a high paying client. The cable is way too short.
(Below: VIDEO of my new Canon IFC (interface) Cable.
Click on video below)