We have been renting DVD's from the Blockbusters in Guaymas since we got here, we just requested a card and they quickly provided one with few questions. This is our 3rd country that we have a Blockbusters card for; 1)US, 2)Canada, and 3)Mexico. Most of the DVD's play without a problem, all you need to do is select Inglés (English) as the language and/or turn off subtitles. On two occasions we got an error that said 'Wrong Region'. Not having a clue what this meant I did a Google search and it seems that DVD producers can encode what region of the world (US, Europe, Latin America, etc.) they want the DVD to play in and the player has a region code embedded in it when it's manufactured. If your DVD has a region code and it doesn't match your player's region code it won't work. Fortunately there is a way around this for some DVD players. Our player is a cheap Cyberhome brand but I found a undocumented hack for changing the region code on the player. Once I did that it would play all the DVD's we rented. Isn't the internet great!
Link - VideoHelp.com