Sharp DV-550 region-free hack
Note: Use this hack with care as you could lock up your machine!
Press Stop, Setup, Still/Step, 1 2 3
You'll find a "LOOPHOLES" menu (the software politely reminds you that "YOU SHOULDNT BE HERE"). There is a Region menu and Macrovision menu plus others (CSS, AUTOMUTE, AUDIODITHER).
Didn't work, or found a better way? Send us your version.