THIS. I have about 8 copies in various locations including one in every bag that ever travels with me. Let the laughing and mocking begin - but better safe than sorry. I also had an immigration agent tell me to always have it with me when entering Thailand as contrary to popular opinion they can't always just "see it in the comptuer" - not yet anyway.
I’ve been emailing back-and-forth with Bangkok bank and it sounds like with my DTV my passport, my ID and my birth certificate. They’re willing to open an account for me.