My Xbox 360 Won't Read Discs: What Do I Do?

Ok my Xbox started doing this yesterday when I was downloading a demo.
My xbox 360 was manufactured around a year ago. There must be something wrong with the lens/drive. I put in a disc, I'll wait it'll make a few loud noises like its trying to spin the disc. Then it'll just stop and go to the open tray message.
Same with any other game I insert. It won't read any disc. What am I supposed to do to fix it?

just the same thing happened to me a few weeks ago.
First it starts with failing reading one game amoung others. Then two discs amoung others and after not a very long time, it will fail reading half of your games and then it will die.

It could be that either the disc is scratched or dirty or that your dvd drive may be almost nearing the end (not working anymore).

Your sensor might have gone out. you can clean the cd drive and the parts with a q-tip...Making sure everything is clean and lubed up properly....

if your 360 is still under warranty i'd phone microsoft up and they'll give you a few suggestions and if none of them work then they'll fix it for free