If you are in a situation where you have a CD or DVD stuck in the drive and unable to eject it, here's a quick tip.  Look at the front of your drive and you should see a small pinhole near the center of it.  Grab a paperclip and straighten it out.  Take the end of the paperclip and gently push it into the hole.  Apply pressure until you see the drive door start to open.  Once you can grasp the end of the drawer slowly pull it out until you can remove the disc.

One word of caution, don't try and force the paperclip as you could damage the drive or disc if it slips, so always gently apply pressure.