I'd just get some corrugated cable sleeving, and velcro that to the rack, and use zip ties to keep the cables within it.
Right now I'm using the old "coil it under the TV stand" method, which works since I have a 19" rackmount powerstrip (connectors are on the back, power switch, LEDS, and two unused power jacks are on the front...looks kinda cool sitting there) sitting right under the front of the stand, which hides all the cable coils nicely.