One of the more common questions we get about Plone development is "Do I have to keep my skins inside Zope? Can I put them on the file system?" - well, of course you can. :)
To make it easier to get started, I have put a package in the Collective that you can download to find out how to create your own Product that will show up in the Add/Remove Products control panel in 2.0 (or via QuickInstaller or external method in the CMF) - so you can easily distribute your skins as an independent product.
"Download it here":http://prdownloads.sourceforge.net/collective/ExampleFileSystemSkin.zip?download - and put it in your Products directory. Install like a normal Product, and look at the 'readme.txt' to get the details on how to customize it for your needs.
I hope you find it useful :)
Alexander Limi - "Plone Solutions":http://www.plonesolutions.com - Training, Development and Support