This mod from LanPartyGuide allows you to disable intro movies.
COD4 Intro Hax README
This executable will give you the option to disable the intro videos with the click of a button. You can also re-enable them later if you wish.
To run the file, simply double click the .exe file
You are free to redistribute this file, but you may not sell or repackage the file. Also, I get the credit.