Add a piece of panelling ($13/panel) to the back of your desk to mask the cord clutter and keep things looking neat and clean from the front.
It is possible to keep electronics exposed without it looking like an explosion. Tuck all cords to one side and use a tie like the Wrap-N-Strap ($9) to fasten them together. If all else fails, a zip- or twist-tie will do the trick!
This is all about following the lines of your desk and running the cables along them. Small, adhesive cord clamps (from $2) will stick to any surface and are a great way to secure your cables in place.
Paintable, self-adhesive products like Cable Raceway (from $11) are a home office's best friend. When run along any moulding or baseboard, they become virtually invisible.