Are you currently using SK2 and like me have qualms switching over to the new Akismet?
Enter Spam Karm 2 Akismet Plugin by Sebbi
You will need to have a WordPress.com API Key for this to work, however you can easily get one by using Flock.
Simply upload the plugin into the sk2_plugins directory and goto the General Settings screen of Spam Karma and enter the API key there.
Sleep peacefully with the added protection