Though the PlayStation 3 is not locked by any particular region, meaning a Japanese PS3 should play European titles, there is one caveat as far as technology is concerned.
Jem Alexander, a new writer for Joystiq sister PS3 Fanboy and the owner of a US PS3 living in Europe, recently picked up a European copy of F.E.A.R. only to get a discouraging message: "This game not supported (80028F10)." You don't need to be fluent in hexdecimal (and if not, why are you wearing those t-shirts, hm?) to feel confusion and resentment towards the supposedly region-free console.
The problem is much less sinister. North America and Japan use NTSC television standards, or 480i, while Europe uses PAL standards, or 576i. Hence, the US PS3 isn't configured to handle the extra 96 lines of imaging. (You might remember a similar problem being noted with European Genesis releases for the Wii Virtual Console.) The solution is simple but costly: all PS3 titles support 720p, so buy an HDTV set.
[Via PS3 Fanboy]