Do your shades have a short life? Do you sit on them, fiddle with them until you break the arm off, or drop them often? If so, this project will probably allow you to use them to make a really fun, geeky-chic necklace. Unless you've completely mutilated them, that is.
See Sunglass Necklace! and 1000's of others - or share your own on Cut Out + Keep