Coding Horror: A Modest Proposal for the Copy and Paste School of Code Reuse
http://www.codinghorror.com/blog/archives/001257.html
"Attach a one line comment convention with a new GUID to any code snippet you publish on the web. This ties the snippet of code to its author and any subsequent clones. A trivial search for the code snippet GUID would identify every other copy of the snippet on the web"