Yep, craic is Irish... At least since I moved to Dublin (Ireland, not California

), I've heard it often enough. I guess, it's a synonym for "fun"
To add to Alisha's list:
city centre = downtown
motorway = highway
bloke = guy / fellow
mate = buddy
I think I've seen "city centre" and "mate" used in L&C fics..
These were my impressions. I'm neither a native speaker of American English nor that of British English. I've just lived in both countries for a while, so I might be wrong..
