Just spotted that it has been confirmed by play-asia that Call of Duty 3 for the Xbox 360 is region free! So get over there quick to place an order! I've found play-asia to be reliable and quick, and have just ordered my copy!
Play Asia Compatibility guide:http://www.play-asia.com/paOS-00-3-xbox360_compatibility_guide-49-en-50-00.html
Note - these are limited to one per customer, I'm guessing to stop eBay tradersfrom taking the mickey!
My first posting - hope it helps!