I use a program called CarryDVD. This will convert any DVD and save to disc. I originally used it to put some DVD on to a PDA. The output can be used on a computer too. Obviously the definition is reduced but as you will watch a DVD on computer from a few inches it is not noticeable.
An episode of the Prisoner, about 30 minutes, is crunched to 100Meg but could be larger or smaller.
carrydvd.com at about £17 and first rate support.