232w ago - To share games downloaded from the PlayStation Store on up to 5 PS3 systems for most games and add-ons all you need to do is create a new user on your system and go to sign-up for PSN and use an existing account.
Just enter your friend's sign-in info then it should say "thank you for signing up" with their name. Then go to the PlayStation Store and click on downloads and just download what you like!
Once the download starts, you can sign off their name and it will continue to download once you sign back to your account. Enjoy!
On a related note, be sure to check
PSN.PS3News.com for the latest PSN links. You can click on the column headings to sort by PSN Title, Date Added, Region and Type.
to clarify, you can share just about anything downloadable from psn, including things not in the store (beta invites and such). for games that have a blu ray version out as well as a downloadable version (burnout, warhawk...) you need to have not only the owners account saved, but also there password. so if they change there password, then it will no longer be able to work.
also, for all DLC, it needs to be from the region of your game. So if you imported soul calibur from japan, the downloadable content must be from the japan servers.
as far as which games are shareable, its a safe bet to assume all games are shareable. ive yet to come across one that wasn't.
this is indeed legal, and sony will no way infract you for sharing games. they built the store to work that way. its a nice little addition in my opinion.