I know of one method.
1. You will need a PAL MiniDV Camcorder that is capable of NTSC (Most Sony Cams these days can playback NTSC as no doubt do others) playback and is DV-IN enabled.
2. Capture contents of MiniDV tape to PC using said camera to your PC
3. Use your editing software to create a PAL 25fps movie
4. Send movie back to PAL MiniDV Camcorder.
HeyPresto!
