I believe the Brits use the PAL system, where as we use the NTSC system.  If you want to use DVD's from all over the world and not have to worry about formats and regions, I suggest you get a DVD player that will take care of it for you.  I have a Malata DVD player, I can play DVD's purchased from all over the world.  It was the best purchase I've ever made.  Check out HKFlix.com.  They have numerous DVD players that fit the bill.  Like I said, I bought my Malata DVD player from HKFlix.com, but they have several other brands.  Good Luck, have a good time across the pond!