usa cd or dvd label that you get from a label maker kit. lay the cd flat on the table and put the peices together making sure the cracks are aligned as if it wern't broken. use a paper towel or something so you don't further scratch the cd, then apply the lable to the cd as if you were just putting a label on it and press it on. but make sure that you can't feel any rigges where the cracks were before applying the label. Maybe you can retrieve some of the data if not all. GOOD LUCK (worked for me)
self help, August 2009