DVD Shrink allows you to copy many DVDs onto another DVD and at the same time, shrink it so it fits.  It’s biggest use is taking a double-sided DVD and shrinking it onto a single-sided DVD.  You loose some quality but it’s usually unnoticeable.  At the same time, this little utility can also remove some of the annoying restrictions on a DVD like the region code.  I often use this program in conjunction with DVD Decrypter.  First I run DVD Decrypter and have it dump all the VOB files into a folder and then use DVD Shrink to shrink them appropriately onto a single sided DVD.