I could really use this feature, too.
BTW, the plugin’s functionality should really be in the WP core.
What about filtering the posts by custom field numericaly? Example:
$prev_post = new WP_Query();
$prev_post->query( array('cat' => $category_id,
'meta_key' => '_my_order',
'orderby' => 'meta_value_num',
'order' => 'DESC',
'meta_compare' => '<',
'meta_value' => get_post_meta($post->ID, '_my_order', true),
)
);
First post in this query results should be the previous post by _my_order. But since comparison isn’t done numerically, this gives wrong results.
