You can share games on PS3. I've never done it but I know it can be done. You used to be able to do it with up to 5 consoles but they reduced it down to 2 on PAL consoles. Not sure if it's the same for NTSC.
I've never done this and I don't know if it still works but here's some intructions.
Quote:
For the “sender”:
1. Purchase and download a game from the Playstation Store
2. Go to account management for the account and delete the billing information from your personal information if the PS3 saved your credit card info
3. Change your password temporarily for the share
4. Give login info (email address and password) to the receiver
5. When the share is completed, change the password
For the “receiver”:
1. In the PS3 XMB menu, add a new user account on your PS3 and sign in to it
2. Select the network on the XMB and create an existing Playstation Network account
3. Use the login information given from the “sender” to create the existing account
4. Login into the account
5. Enter into the Playstation store
6. Click on “Download List” on the upper right near the person’s userID and select the game you wish to download and hit download
7.Once u set background download…exit game and log in urself…notify sender that u done.
Although it is risky you should trade with people you trust.
And this is LEGAL.