I was sick of the mess of cables to hook up cameras, external hard drives, phones and other paraphernalia to my computer. Luckily much of it has moved on to use the various sizes of USB, but some companies still use proprietary shapes.
I made use of the metal case on the computer to organize things a bit.
Step 1: The Only Step...
Glue a neodymium magnet to a hard part of the cable. I used Gorilla Glue and it's standing up well so far. I glued mine to the PC side USB end on one side and the choke (the lump in the cable) on the other side. I like the magnet on the choke because I can grab the end of the cable and the magnet just pulls off and flops into place against the case, no fiddling.
If you don't have enough USB plugs to keep the other end of the cable plugged in, and if you have a choice of cables lying around, use different colour cables so you can distinguish between them without having to follow them along to the computer.