So you have a DVD that you want to store as a file instead of lugging the plastic around, and wondered how to do this on your linux box. Wonder no more! Handbrake is a nifty cross-platform dvd ripper that you can use in the linux shell (this makes you look well hard). If you are soft, you can also install it on windows or OSx, but I digress. Obviously you should only do this for home DVDs that you own or have permission to duplicate, ignoring this will result in DIRE consequences. DIRE!
Download the linux CLI version from http://handbrake.m0k.org/?page_id=8, then untar and copy the binary to your /usr/bin directory (and make sure its executable)
wget http://handbrake.m0k.org/?page_id=8 tar zxvf HandBrakeCLI-x.x.x-Linux_i386.tar.gz sudo cp HandBrakeCLI /usr/bin/ sudo chmod +x /usr/bin/HandBrakeCLI
Now just rip your DVDs, you dont even need to mount them (but you can if you want to). Its taken about 25 mins for a dvd on my lappy, but YMMV. You will need to change the path to your dvd device, or you can just use the mount point instead.
$> HandBrakeCLI -i /dev/cdrom -o /home/me/pr0n/myhomedvd.mp4
That will yield an 800ish mb mp4 file, but have a look on the handbrake site for all the other goodies you can use.