One thing about Game Sharing mentioned in this thread is wrong. If you delete the user, you won't be able to play the game.
So this is what you have to do (just to be crystal clear) -
The person receiving the card creates a dummy PSN account (If he cannot be assed to do that, he simply uses his existing PSN account) and adds the PSN card funds to this account and purchases the game(s).
He gives his account details to you.
You have to create a new user on the XMB and goes to "sign up for PSN" and chose "Use existing account" and sign in using the details given to you.
Then you accessthe PS Store --> Download list and downloads the game(s).
But you will have to keep the PS3 user account you created in the XMB to keep playing the game you just downloaded.
