I am reminded that I neglected to include any links! The most reliable website I found is: http://superdrive.cynikal.net/ This offers downloads for all the PB DVD drive versions for which hacks are so far available. You need to check the version of drive you have in the System Profiler (About This Mac in your Finder pulldown menus). My drive is the Matshita UJ-815, for which a hack is now available. You must not run a firmware hack for the wrong type of drive because that will permanently damage it. My drive had been converted by a previous firmware update (from Apple) to UJ-815A, so I had to find another hack to "downgrade it" before I could upgrade it to a region-free drive. Happily, that was also on the website. If your PB has the UJ-816 drive, then, as I understand it, that still does not yet have a region-free hack. Hope this is a help.