This is one of those areas where personal preferences come into play. I happen to like these cable ID tags [link text][1]
[ID tags][1]
![alt text][2]
They're particularly good when labeled with a Brother P-Touch.
[1]: http://www.macconnection.com/1/1/45916-black-box-corp-black-box-cable-id-tags-5-8-x-2-white-100-pack-ft912.html
[2]: http://service.pcconnection.com/images/inhouse/5125208.jpg