Rip the movie to the hard drive using your favourite ripper (DVDFab HD Decrypter). The 'VIDEO_TS' folder can be copied/pasted or dragged to the flash drive. If the ripped movie is too large to fit on the drive, it can be shrinked to fit using 'DVD Shrink'. Any decent media player (VLC) will open the folder and play the movie. Memory sticks are formatted as Fat32 and Fat32 drives are limited to the size of any one file (maximum 4GiB). Note that this is a maximum for a single file - not the sum of all the files.