When doing either audio or network installations, labeling each cable is always a pain. You want something that is legible, durable and will withstand the jostling of being moved around.
Paper tags are out, tywraps are out. I use a Brother tape-writer with a USB interface and when I apply the label, I overcoat it with a couple inches of clear packing tape. Works OK.
CableLabels are genius -- you get an 8.5*11 sheet of labels with an adhesive clear cover 'tail' attached and they are designed to be run through your laser printer -- nice and durable.
Check out CableLabels. Price varies from $1.99/sheet to $2.49 depending if you have color and on the size of the label.
I have a couple sheets on their way -- moving my electronic music stuff out of the DaveCave(tm) into the house and having to re-do all of the wiring (spending some quality time with my soldering iron)...