You can now download The Bravo Map Pack from the Xbox Live Marketplace for Call of Duty 3. The Map Pack costs 800 MS points.
"The Bravo Map Pack unites three new multiplayer maps with two classic PC maps from Call of Duty and Call of Duty: United Offensive. Storm hilltop abbeys, maneuver alleyways for the perfect ambush, or battle in the nighttime shadows of a riverside town in three never-before-seen maps. Gare Centrale, one of the original Call of Duty's most popular maps, brings its unique layout of warehouses, water towers and a train depot to Xbox 360 for the first time. Marseilles delivers United Offensive's exciting blend of vehicles and vast, open combat to next-gen."