I noted that you were asking for AnyDVD over in the suggestions for future giveaways. I agree that its a really useful software to have. I bought it a few years ago to do exactly what you suggested it was good for as I'd had to buy a new disc for one of my favorite games and a few others were looking rather well worn. Still, there is another legal alterantive. Try the following site:
http://m0005.gamecopyworld.com/games/gcw.shtml
I use the NoDVD patches for all my bought games now, which keeps them in pristine condition. It also saves me the bother of having to put a DVD in the reader. you can just start your game up without any fuss. They release one for every patch that released, though it takes several weeks for new games to have noDVD patches usually.
I hope this is a useful alternative for you.
Regards
Whiterabbit
p.s.
Some say that they are illegal, but this is not so; though they can be abused if youre dishonest enough...........I wont go into details, lol.