Design a CD Coaster

CD coasters can make great gifts. It's really easy to individualize them and tailor them for the people you're giving them to.

Steps

Gather your old CDs that you definitely don't want anymore. This is a great use for unreadable CDs from failed burns. If you decide to use old CD-Rs, be careful of personal or confidential data on them.
On the surface of the CDs, glue on sea grass, gems, photos, or magazine clippings. Be creative!
For a more classy look, draw, paint or leave the CD blank.
Spray the finished surface with clear varnish to help protect from moisture. Don't use shellac; it isn't moisture resistant.
Coat the bottom of the CDs with felt. Thin cork from auto parts stores that are used for making gaskets could be used instead of felt.
You have new coasters!
Finished.

Instead of decorating, glue two CDs together with the bottom sides facing outwards. (Gluing two CDs together helps you keep your coasters apart from useful CDs that might also be floating around on your coffee table.)
Remember, when gluing on raised objects, keep them close to the outside edge so a glass can sit in the center of the coaster.
Write humorous or surprising labels on CD-Rs (e.g. "Sexy neighbor undressing disc 2").

Do not attempt to use the decorated CD in your computer "just to see if it will work"..