Cable Wrapz - pack of 6 for $7 at Compusa
They work something like a little girl's pony tail holder. Very practical - easy to attach, snug fit, stay in place. Besides the computer area, I use them on hair dryer cords, lamp cords, and other cords and cables throughout the house, too.

Also check out the online retailer CableOrganizer.com to get more ideas.