It is my understanding if you personally own the DVD your copying for archive purposes it is ok. Obviously it is against the law to copy rental DVD's or reproduce DVD's for friends.
There are some retail products out there, for example, Best Buy has a product called ICopyDVDs2, however, it states in the product information if your going to use it for copy of retail type DVD movies, versus personal created DVDs, you have to use a freeware product called DVD43, to crack the copy protection first. It also has the ability to be used with the newer Dual Layer DVD's.
Keep in mind many professional DVD's are Dual Layer, they will not fit on a standard DVD+R or DVD-R disk. Now there are products out on the internet like DVD Shrink, DVD Decryptor, etc... that will crack the code, and allow you to just burn the movie only and not the special features. This helps to get it to fit on one standard DVD without any or little compression. In many situations, even with compression, you can't fit an entire DVD plus special features/menus, unless you have a dual layer burner in your computer.
There is also the issue that not all DVD players will play certain DVD media. Some players like DVD+R's and others like DVD-R's. Computers usually don't have a problem with either technology. Just to warn you that the media used on retail DVD's is different than the media you buy in the store, so you may or may not have issues.
I used to do a lot of this, and got to the point where it was just not worth my time. I'm a computer geek, and still got frustrated with the many problems occur trying to achieve a flawless copy. Even when I purchased top quality name brand media, freezing/stuttering can be common. Not to mention the time it takes to actually Rip/Burn/Verify your copies.
All the power to ya man.
