You are likely to significantly increase your blog speed by removing all of your posts / pages from the database. I saw databases with 500 posts / pages shrinking from 35 megabytes to 5 megabytes after cleaning, which led to a significant increase in the speed and usability of the blog. Run this query in phpmyadmin, modifying the table if necessary, and pre-run the database backup.
DELETE a,b,c
FROM wp_posts a
LEFT JOIN wp_term_relationships b ON (a.ID = b.object_id)
LEFT JOIN wp_postmeta c ON (a.ID = c.post_id)
WHERE a.post_type = 'revision'
Or use this plugin: http://wordpress.org/extend/plugins/bulk-delete/
Then add this line to wp-config.php to stop the revisions:
`define ('WP_POST_REVISIONS', FALSE);
And then in phpmyadmin, optimize the database by selecting all the tables and then in the drop-down menu. This will remove all overhead after version cleanup.