*. Make ISO image files of your DVDs.
*. Add/Remove or skip copying subtitles or certain audio/video track before copying.
*. If you have k3b installed (if you use KDE then it comes by default) then Backlite also has the ability to burn the extracted data to DVD too.
*. With the help of Mencoder (MPlayer's excellent encoder!) it can convert the DVDs into MPEG-4 format as well...
These are just a few of its main features to name. Anyhow, if you use Ubuntu 11.04/10.10 or 10.04... you can easily install Backlite using the below command (using a third party PPA channel).
sudo add-apt-repository ppa:ferramroberto/k9copy
sudo apt-get update
sudo apt-get install backlite