Louise Bremner <log.NO.SPAM.HERE@gol.com> wrote:
>Not so much of a "howler". I'd guessed at its meaning from films, and so
>took it as a polite brush-off: "Thanks but no thanks". So I got somewhat
>miffed when someone used it at me, until he later came back and said he
>now had time--the movies never show that bit.

I've heard "rain check" used both ways...

<Friend 1> Can you help me move this weekend?
<Friend 2> uh....  I think I'll take a rain check.

or

<Colleague 1> Wanna go for lunch?
<Colleague 2> No, I've got a meeting; can I take a rain check?

I think the first usage (the polite brush-off) is typically only used when
you're good friends, or at least don't mind offending the other person.

That said, maybe the Americans don't use the phrase in the brush-off sense.

 - awh