USB, Serial, and other cables that have a small plastic frame attached to them, right over the top of the plug. Each frame contains an image of the user's choosing, either printed on their own paper or ordered from the manufacturer's website (upload, click, and receive an image in 6-10 business days).
even the most hapless among us can truly say (after paying printing, shipping, and handling costs) that we have a girl in every port.
Also available as dummy plugs.
EDIT: Heavily modified shortly after posting