Disabling WordPress Post Revisions
WordPress 2.8 has what I would call a nasty default habit of saving way too many drafts / revisions during post editing.
I disabled this by adding the following to my wp-config file:
define('WP_POST_REVISIONS',false);
To delete all the revisions you already have in your entire WordPress database, insert and run the following query in your DBMS:
DELETE FROM wp_posts WHERE post_type = 'revision'
This will still keep your single autosave/draft.