Get the post_id of a new post

Question

There are several ways to get the id of a post after it has been saved (auto, etc.), but is there a way to get the post id immediately after you create a new post?

I am trying to create a directory using the post id, but I cannot seem to get a static post id.

the code below seems to work but I get an auto incremented id back every time the new post auto saves the draft, I continually get a new number.

function myfunction( $id ) {
        if (!file_exists("/www/foo/blog/wp-content/uploads/" . $id)) {
            mkdir("/www/foo/blog/wp-content/uploads/" . $id, 0777);
        }
}
add_action('save_post', 'myfunction');

I would like to get the post id that it will be saved as. Surely WP has a method for determining this correct? Or does the draft auto save every minute incrementing the id by one until the actual 'publish' button is clicked?

thoughts?

cheers! bo