Good question. You might want to check out the information at Videohelp.com site as it has that type of information. Also check out AVSForums site. I know people buy Blu-Ray movies from Amazon's UK site all the time as they have great deals and the the Blu-Rays are region free.
EDIT: If you go to the following Videohelp link, you see another link that says "Region code free hack here", see if that has the info you require.http://www.videohelp.com/dvdplayers?DVDname=nsz-gt1