User blog comment:Bovell/"Call of Duty: Project Colossus" = Modern Warfare 3? + Micro-transaction Call of Duty for China in the works/@comment-79.126.149.231-20110512111709/@comment-1889554-20110513114545

About that whole "attachment skill" thing.

For MW2, to get a Noobtube, you just had to get 10 kills with a weapon.

For BO, you had to accumulate 3000 CP. That's 300 kills, 2-3 level ups, about 5-20 challenges completed, or any combination of the two.