Using a psn account to download free stuff?

May be...

well someone showed me a youtube video which shows how to get the extra maps for free for cod4 by making a new username and putting another persons account under existing account and downloading the downloads the person did under that account.will this really work,my friends want to get the maps for cod 4 from me and by the way would this work to dowload other stuff?

Yes, it does work. One of you two had to have bought the maps.

Then, what you do is make a new user. Then go in PSN (click on sign up" then click on log in existing account & log in as the ID (who ever bought the maps) then go to download list in account management & download it from there. log off & switch to original account. install. Done!

I never did think of that. Thanks!