Interesting...

> If I leave RETURNTRANSFER as 0, their page prints out as if it were mine
> (base url is the one I sent them, with their variables appended).

Perhaps you can capture the url with javascript (client-side), but I
doubt it. This will likely return the url of the page you originated
the curl request from.

> With RETURNTRANSFER set as 1, I've tried accessing the $HTTP_GET_VARS
> and $HTTP_POST_VARS but there is nothing there.

This is to be expected, whether you use 1 or 0, as these arrays are,
like the location property above, associated with the originating page.

> I'm trying to mimic the action of the external site's form pages so that
> I can do things behind the scenes(server side).

This seems possible, but I can see how there would be the beating of the
head against the wall. Sorry I can't be of more assistance.

Pete.

-- 
Pete James, Advanis