A) Get a grid of garden mesh. This gives you a 2D substrate you can clip cables (and USB hubs, outlet strips, etc) to. You can mount this on the underside of your desk, hanging from the back of your desk, or in a cabinet if you want. (You can see my implementation at the right side of my desk, here http://www.flickr.com/photos/capybararancher/6705805105/
My approach was: simple cable runs to that one cabinet, which becomes the patch panel between devices. All slack for cables is taken up there, and cuffed (see below) to the grid of mesh.
Only downside: I had to buy a 40-foot roll of garden mesh, and only used 21" x 21".
B) Get some cable cuffs: www.cablecuff.com/ I find them handier than velcro ties; they're cheap and durable. You can get them by the handful at Home Depot.