This past Thursday, I received a very exciting phone call from my 12 year old son.  He said he is now playing one of his video game CDs that he hasn't been able to play for over two years.  So I asked him how was this possible?  He simply said "mayo".  What?...I said...yes, mayo.  When I arrived home, there was my son playing his "old" video game with eyes firmly fixed on the TV.  After several tries, he finally put the game controller down and showed me what he did.  He simply took a little of bit of mayo and rub it on the CDs with a cotton cloth.  That's it?...I asked.  "That's all it is too it", he replied.  So when he was finished with his game, we proceeded to clean his other scratched CDs as well.  Now, they play like new.  So what's the key?  Well, the mayo fills in the scratches.  And if that's not enough, you can try toothpaste as well.  Apply the toothpaste (any kind but baking soda) to the CD and let stand for 15 - 30 minutes, rinse off, then dry.  This also works because the fluoride ion in the toothpaste fills in the scratches on the CD.  However, if your CD is heavily scratched, then don't bother.