Some updates

I've been chatting on IRC with Marek and, as ever, he had some other ideas I hadn't thought of, focussing on the destination parameter you can place in a querystring in Drupal.

If you don't mind the URL containing a querystring, you can use a link like this in your menu to redirect after form submission:

node/add/page?destination=my/destination/path

Alternatively, you could also probably achieve the same by messing with the '#action' field in the form, something like:

<?php
$form
['#action'] = $form['#action'] . '?destination=my/destination/path';
?>

I haven't attempted either yet, but both seem like reasonable solutions. =)