Inspired by http://www.thingiverse.com/thing:70549. I needed something with a smaller opening to keep my cables from falling out, so I whipped up something similar. It holds the USB cable for a Samsung Galaxy S4 perfectly. It takes just a small amount of pressure to "snap" it into the holder; enough to hold the cable, but not enough to damage it. See time-lapses of the things I print here: https://www.youtube.com/channel/UCQ9nW8XQAPWKGGKRd9LFQNQ