Instructables has a tutorial on a CD repair technique designed to bring nearly any disc (barring any cracks, breaks, etc…) back from the dead. The fix requires you to heat the underside of the CD over a gas burner, boil it in water and dry off your freshly resurfaced disc. The process seems to leave a slim margin of error, so if you’re trying to recover something valuable, you better know what you’re doing. [Instructables]