Generally speaking, PS3 games are all region-free, and the system doesn't enforce any sort of encoding itself. The sole exception that I'm aware of is Persona 4: Arena, but otherwise, you're golden. This doesn't apply for PS1 or PS2 games, obviously.
As for DVD/Blu-ray, that's a different story. It won't play DVDs from different regions at all, unless they're region-free, and it doesn't do PAL/NTSC transcoding. Most Blu-ray discs aren't locked, but I've run across a fair number of UK editions that are, and in some cases, menus are in PAL and you can't launch it properly even if you can technically play the movie (Zatoichi comes to mind here, grr...). I usually check against sites like blu-ray.com and blubeaver.ca to verify the actual encoding.
I currently use my PS3 for import games and BRDs, but have an Oppo DV-980H for import DVDs. Pretty much any of their players will do the job admirably.
