You could use the Snapmatic phone app in-game, but the Steam overlay is much easier to actually get to the pictures after you take them (I got the game through steam so it's what I use most of the time).
@xanadu: The progress transfer I think was only for GTA Online. My character from the 360 carried over just fine, with everything I had.
Spent two or so hours in GTA Online with a friend and about two more starting the campaign. It runs great, looks pretty good (not everything is maxed out, but I'd rather have a nice high FPS), and First Person mode is just as awesome as I thought it would be.