Here is New Zealand blank writable DVDs cost quite a bit more than retail DVD movies (about $NZ80 compared to $NZ40 for a movie disk), so at the moment there isnt much point. Give it a few months and things will be a lot cheaper and easier.
Shoot dude. Look around at DVD sites. This isn't one of 'em. Not to sound rude, but the first thing you'll read is that is can't quite be done yet.
1) Most (all) movies these days are dual-layer discs. Burners can't burn more than one layer. The technology to burn two layers won't be around for several years to come. The way around this is to buy two DVD-R disks (see point 2). What you then have to do is "remaster" the disk - copy it to your computer and use software to re-encode all files (takes about a day) and burn one half of the movie at a time. You need to do this because there are codes on the disk that tell the DVD reader to resequence on the second layer - If you burned a movie on to two DVD's without remastering, you wouldn't be able to read the second disk (or so I'm lead to believe)
2) Disc prices. A DVD-R (write once) disk is something like $10 in quantity. A movie is $20-$25 ($15 at a reseller). DVD-R's require two disks. Hey, a couple bucks more and a few hours less time and you got a full, legal copy.
What to do (I figure. Haven't seen it done yet):
You've all seen DIVX movies compressed to 600-700mb? Those are compressed in a major way and most of them are pretty good quality, right? Well, instead of that major compression, just compress a DVD by, oh, 2 times and it will fit on a regular DVD. Granted, you'll be cutting out a little quality, but unless you've got a $20k TV and a $5k stereo, I doubt you'd see the diff.
I hate bad news. This is simply what I have learned after many exhausting hours of searching forums. PLEASE PROOVE ME WRONG! Of course, I do not do this sort of thing and would never consider making a copy of copyrighted material.