Yahoo Export Contacts to CSV Broken for Facebook!
Import your facebook contacts into Yahoo.
Export your yahoo contacts to an open format.
Import the open format contacts into your system of choice.
This solution has worked for a while but is now broken. Yahoo no longer supports exporting contacts that were imported via facebook (personally, my bet is facebook made them). Fortunately Yahoo still supports printing these contacts to a simple HTML file which we can then parse ourselves. Even more fortunately someone already wrote an automated tool for us, instructions and download link here. It is only a matter of time before yahoo blocks this method as well so get to it.