Did you end up with a scratched disc from your Halo 3 purchase of the Limited Edition or Essentials Disc and the store has sold out? No problem, ship it off to Microsoft and they will get you one back as soon as they can with the link below:

If, for any reason, you have a damaged Microsoft Xbox 360 disc and like to replace it, please review the information below:

THIS PROGRAM IS GOOD ONLY FOR XBOX 360 CONSOLE OWNERS IN COUNTRIES WHERE XBOX 360 IS SOLD AT AUTHORIZED RETAIL LOCATIONS.

NOTE: This program covers the Halo 3 Limited Edition Game Disc and Essentials Disc at no charge through 12/31/07.
Microsoft Xbox 360 Scratched Disc Replacement Form