If Your Game Disc Isn’t Working, Boil It
(Note: I wrote this entry months ago, but neglected to post it. It still seems relevant and not widely known, though.)
The description of why it works (post 10) makes it sound like it’s more applicable to demo discs, which are more likely to warp during shipping, but there are anecdotal comments about it working for retail game discs as well. I may give it a try on my dead Final Fantasy XII disc.