Log in with 2 accounts on one PS3?

You know how Xbox has that thing were you can use a different gamertag for every controller so that person can use their own stats and earn their own achievments? Does the PS3 do that, or is my friend stuck with the "guest" label?

I heard from someone that you can do that in Resistance 2, but im thinking more Warhawk here.

You know how Xbox has that thing were you can use a different gamertag for every controller so that person can use their own stats and earn their own achievments? Does the PS3 do that, or is my friend stuck with the "guest" label?

I heard from someone that you can do that in Resistance 2, but im thinking more Warhawk here.

runekey