I was wondring if the superdrive that comes with the apples allow you to copy a dvd movie?...or are they made so that you can only create your own dvd's and use as storage?
You can copy DVDs using apps like DVD Backup (available here)
It's just a normal DVD-RW drive... so you can do anything... but since most Hollywood DVDs are 7 to 8 GB, and you can usually only get 4.7 GB DVD-Rs. And plus, many of the Hollywood DVDs are also double layered, and you can't burn double layers with a Superdrive (or any consumer DVD-R drive for that matter). So it's going to be hard finding a DVD you can burn... but they're there. I've managed to burn about 4 or 5 Hollywood DVDs myself.
The instuctions on how to burn it correctly come with the app...
Most Hollywood DVDs come with a special lock called CSS Encryption, and so you can't copy it just like that. That's also why you can't just drag the VIDEO_TS folder out from the DVD and play it. DVD Backup removes the CSS encryption and other pesky stuff like Macrovision.
I don't think people would make software like DVD Backup if it was that simple.
I don't see why going from a single layer to single layer would be an issue. But with the exception some of the first DVD titles I don't think very many single layer DVDs are released. All of the "extras" take up space. Plus, it wouldn't supprise me if studios intensionally used dual-layerd discs, when a single layer would do, to help prevent piracy.