I have a tower computer case standing on the floor under my desk, with lots of peripherals both below the desk and above the desk. We're talking router, switch, IP telephony adapter, power strips, telephones (yes, plural), external hard disks, a UPS, a printer, the obligatory monitor (would love to change that into a dual monitor setup, which would only add cabling), mouse, keyboard, a 2.1 speaker set, and more. This obviously leads to a lot of cables going back and forth between the various devices. Despite repeated attempts to reduce the clutter, this very quickly grows into a rat's nest of cabling and I keep having to trace cables through the mess to find where they lead.
Several of the items require the use of their own wall-wart transformers, some of which are relatively heavy.
I don't want to do anything that causes permanent damage to the desk. The desk itself is right about 2 cm thick.
I don't mind the cables themselves being visible, but I do mind it being so difficult to know what item uses which cable is connected to where. None of the items are wireless, and for various reasons, I want to keep it that way.
How can I keep the cabling organized, as well as ideally somewhat out of the way?