It's more complicated than that, but fairly simple affa. Basically, you can make an e-mail acct, and PSN acct. Fund account, buy game, and remove payment info. Then, you can pass that info to 2 "phantoms", who can sign in, download, sign out. They never touch the account again and just play it on their main, and it will work. Then their accounts are deactivated, so it can be passed to the 2 other 'main shareholders'. They would have permanent access to the account, until deactivation. Thus 4 people could share a ps3 game so we could have 4 winners instead of 1.
And if people are diligent about playing the game and don't mind, they can pass their share off to someone else when they are done. Win for everyone.