Buy Portal 2 for PS3 and get it for PC too.

[Blix]

Originally Posted by Bube

If there are those of you who don't like the free offer, you could just gift it to me over Steam. Or I could pay $5 or something.

If you have to link your PS3 copy to your Steam Account (possible) then I don't think they can gift it to you. And that's what I think they'll do since the PS3 version will be... "fully supported by SteamWorks, allowing for auto-updates, downloadable content, and community support directly from Valve." So you can have copies for both of them but only one person logged into steam can play it at any given time.