This version adds post meta editable fields. These are a little different from the others. To add a custom field editable meta, you have to add something like this inside The Loop in you WordPress theme:
<?php editable_post_meta($post->ID, 'my_key', 'textarea'); ?>
The first argument is the current post id, the second is the custom field key and the third is the type of field you want (input, textarea or rich).