I've always heard that there are things that Americans may say or do that would be a no-no in other cultures because it takes on a different meaning. And vice versa. The other day I had my first no-no.
We had an away day scheduled North of Dublin for the group that I was in (I'm officially FIDS now so I'm no longer BRS, but thought I'd attend to get to know meet more people). Most people "worked from home" on the morning of and went out there for the actual meeting in the afternoon. However, some people came into the office and the people that sit around me where in. I had meetings with the partner that morning and so she said that she would take me to the away day since she was attending as well.
When the others came in they asked me if I wanted to go with them and I said "No, thanks. I have a ride." Then I got "Oooh nooo. I wouldn't say that here. It means something 'different'." I got the picture.
I think the following phrases would be very common place in the US:
"Do you need a ride?"
"No, thanks - I've got a ride."
"Because I could give you a ride."
"I'll just get a ride."
I'll slightly adjust those in the workplace. :)