All small filetype icons come unmodified from the FatCow Web Hosting
"Farm-Fresh Web Icons" icon set and carry their original license.

http://www.fatcow.com/free-icons

License information (from the link above):

These icon sets are licensed under a Creative Commons Attribution 3.0 License.
This means you can freely use these icons for any purpose, private and
commercial, including online services, templates, themes and software. However,
you should include a link to this page in your credits. The icons may not be
resold, sub-licensed, rented, transferred or otherwise made available for use.
Please link to this page on fatcow.com if you would like to spread the word.
