Videolan Media Player allows you to take screen captures of any movie your are playing, and is an all-round fully featured video player. It does far more than the likes of PowerDVD or Windows Media Player, and best of all, it's free!! Even allows you to playlist .vob files alongside dvds - top notch if you like to play a Dolby trailer or something before your film to check the surround etc is working. I believe it may also be region free, at least the linux version of it is, which is also handy.