I went to Best Buy to get a copy of Year Zero (I have Year Zero! Yay!), and I sat in my car while I unwrapped it and scanned the booklet for any cool pics (leaving the CD case open on the passenger seat, in the sun.) Alas, I didn't find any cool or mildly disturbing pictures in the booklet (although there were some in the CD case - you'll see in the pictures I took). However, when I moved to put the booklet back in the case, I was amazed to see that the CD had changed completely! I grabbed my digital camera (hey, you never know when you'll need it) and snapped a couple of pics.
As you can see, the CD at that time was white with black lines and coding, reminiscent of several of the promotional websites for Year Zero (check out the NIN Wiki to see what the hell I'm talking about.) I figured out pretty quickly that it was either the sunlight or the heat that caused the change, so first I closed the CD case and let it sit for a bit in darkness. Nothing. Then I held the CD up to the air vent and let the cold air blow on it, and bingo!
This is halfway through the process. Once it got totally back to what it originally looked like, I tried to take a picture of it, but I kept getting flare (and then the light I was stopped at changed), so I waited until I got back to my dorm. It heated up again during the walk from my car to my dorm, so I put a container of half-frozen apples on it:
That made the change occur pretty quickly, and I got a good pic of the original state of the CD (check out the artwork/pictures in the CD case! You can't tell from the picture, but the left hand is holding a Bible.)
If you look at it close up, you can still see the lines and numbers that appear when it's hot:
I also got the Hellogoodbye album (Zombies! Aliens! Vampires! Dinosaurs!), just because.
P.S. - If anyone is interested in the sorta-MMORPG-type Kingdom of Loathing but don't want to commit to an account until you know if you like it or not, comment here or email me or something and I'll give you the username and password to my alt account, because KoL is an awesome game and everyone should play it <3