With my HP 300i DVD Burner I Use this software to copy DVD's:
http://www.dvdxcopy.net/?a=4603 DVDXCopy
(hurry they are trying to pull it.. law suits etc)
I can copy a DVD if it fits on one side in about 15-20min
And raw data to 4.7gig in about 30min, I don't do many
of those.
The media is cheap to at a little more then a buck for 4gigs
of space.