Mollom for Expression Engine
Upload to /system/expressionengine/thridparty/
Enable in the extensions menu and add your keys
You can create an account at http://www.mollom.com
How it works
Currently Mollom for Expression engine will check all comments using the hook "insert_comment_insert_array". If a comment is flagged as spam it will automatically be closed, if the system is unsure it will become a pending comment, if its not spam or penning the comment will be posted.
This is complete automation.
**Future**
working on a second part to track then number of comments that have been tracked and how many post fall into each category of spam, ham or unsure.