I just mounted a classy aged brass coat hook on the wall beside my desk and wrap the cables around it. For $3 at Home Depot, its a cheap and elegant fix.
I got tired of the long HD650 cable as well and built a shorter 5' long cable for it to use at my desk. Makes for less clutter and risk of rolling over the cable with my chair. The other option is to coil up a portion of the cable near the plug and have that sit on your desk to shorten it.