About that beer I owe ya

At the start of Half-Life 2 there's a character called Barney who disguises himself as a bad guy, but then reveals himself and says "About that beer I owe ya". This is because he's also in Half-Life 1 and he has a dialogue line where he says something about buying the main character a beer. So now this is something that Joe says sometimes, except with the word "beer" replaced with other things.