Yes. A PS3 game from any region will work on your PlayStation 3 console. So you can but an American game while on holiday and it will work with your PAL console. PS1 and PS2 games, however, are still region-encoded. So foreign titles will not work on the PlayStation 3. Blu-Ray movies also have region-encoding, so you can only purchase movies from within your region.
Is the PlayStation 3 region-free?