Can I download a PS3 games from PSN on my own system and then download the same game on other PS3 systems?

There's this game I bought and downloaded from PSN (the title is Rainbow Six Vegas 2). I want to know if I can actually download the same game into my friend's PS3 as well, without giving him my PSN login.

Can I do something like logging into my account on his system, then start downloading the game, and after that has started maybe log out and he can log in with his own ID? I am scared that the download may not continue if i do that or may not be activated.

Is this possible?

It's possible to share PSN games between PS3 systems. There's a thread on the SomethingAwful forums that goes into a good bit of detail as to how to do this.

It appears to be at least acknowledged and ignored by Sony, but keep in mind that you should be very careful not to violate any of the terms of your PSN agreement, lest you lose your games or access to the online support of your console. This process is also not without risk, and your "friend" might do something dishonest and cheat you.

Do note that recently Sony changed the rules, so that you can only have 2 PS3 consoles sharing a single copy of a PSN game.

I think now Sony have changed the rules to only allow you to have the game shared on 1 PS3, one PSP and one PS Vita im not sure though