Hello
I love to have some DVDs on my E71 when I travel (takes the sting out of long waits at airports and bad or no selection on airplanes) and I've found a very simple way to do this that I don't think has been mentioned here.
Use the program "DVD Catalyst": there are various versions, including one free one, and they can be found at http://www.tools4movies.com/ (disclaimer: I have no financial or any other connection to this site). Use the setting for iPod Classic/Nano/Video 320X240 at the upper right and adjust the size of the converted video at the bottom according to how you want to balance file size with quality.
Once you've converted your movies, load them onto your memory card directly. You don't need to use the Nokia Video Manager and loading them by connecting your memory card to a USB port is much faster. Be sure you put them in the Video Clips folder on your card.
Put the card back into your E71, open Real Player, go to Options, Open, Saved Clip, Menory Card, Video clips and choose the movie you want.
I hope this is helpful. Maybe I'll see you one day sitting in an airport or on a plane staring at your phone!
Fred