Paginating long posts using WP-Paginate plugin

I have this working great for paginating category pages, the main index.php page great…however is there a way to use this to paginate long posts into several “pages” ? If so what do I put into single.php ? I tried using:

<?php wp_link_pages('before=<p class="postpage-paginate">Pages: &after=</p>&next_or_number=number&pagelink= %'); //display next and previous links for long posts/pages?>

but it didn’t work.

http://wordpress.org/extend/plugins/wp-paginate/