To take advantage of the Steam features, users need to link their PlayStation Network (PSN) account to Steam, either by selecting a new Steam account or using an established one.
Users won't need to do anything special to access Steam via the Portal 2 game for the PS3; instead, all a user needs to do is to press the "Select" button on the PS3 controller. The overlay will allow users to play cross-platform with their friends who have a copy of the game for the PC; plus redeem downloadable content registered to the PC or Mac, view achievements, news, and friend profiles.
To access Steam Cloud (the saved games) users will need to press the "TRIANGLE" button from the save/load screen, then select the number of saves to back up.
There's also an additional bonus: bundled with the PS3 version of the game is a code to play Portal 2 on a PC. While that will allow users to play Portal 2 on their PC, the additional copy can't be used to play in cooperative mode with the PS3 player, Valve said.