You can back you dvd's up by converting them into the DivX format. DivX is the name given to a video codec which is based on the MPEG-4 compression format. Using a player with the codec you can watch them on you computer. The simplest sotware to use is Easydivx which will rip and convert the dvd for you on to 1 or 2 cd's in a few very easy steps. The quality is remarkable good.
http://easydivx.does.it/
Of course there is other software.
A Few Statistics
form : .avi
Resolution : Variable, most common : 640x480 or default PAL/NTSC
Bitrate : Depending on resolution/sound bitrate. Most common : 650MB stores 80-90 minutes at 640x480
Quality : VIDEO - Variable, most common : similar to SVHS/DVD ; AUDIO - Variable, most common : CD Quality+ (48kHz, 96kBits, stereo)
Encoding time : 2-4 frames per second on a PII-350
You can download a Divx player from http://www.divx.com
Also try http://www.divx-digest.com
http://www.divxmovies.com/
http://divx.link.st/
http://www.divxcrawler.com/
you can also find films already converted, in the Divx format, on the net but they are rather large in size.
Add a graphics card with TV out and your laughing.....
nobbly :+