If you don't want to invalidate the warranty then you will have to look at other options. If you are going to somewhere in Asia then see about getting a stand alone portable DVD player/viewer that will be muliti regional, or get an external DVD drive and change the firmware of that instead, of course that will invalidate the warranty on that but it would be a cheaper option that the laptop.
I guess at the end of the day if you want to do something that may or may not be strictly "legal" then YOU have to accept the consequencies, sorry.
