Most DVD players (like my Panasonic) feature a settings selection where you can play back a DVD in PAL or NTSC.

Having said that i have an American Panasonic GS250 camcorder that i upload at 29.97fps i then do all my editing save and burn using the NTSC set up and it plays fine through my DVD without the need to adjust the settings.

Only when i play directly from my camcorder through my DVD player do i need to swop from PAL to NTSC on the DVD player to get a good picture and sound.