Starting with 22nd of December 2010, I updated the Newbie group to contain only users with 0 posts and created a "good users" group for the rest. Now, the Newbie group can only post in the Newbie board WHERE the posts are not counted. Also, the newbie board is not visible to the world, only to registered users. So spammers can post there as much as they want )also keep in mind that akismet is still doing it's job flawlessly)
Now, when you are a legitimate user wanting to post something somewhere but you're newbie, you will post your topic there and also specify where you want it to actually reside. Then I will get an email once you post and in the next few hours/days will move the topic to the appropriate location which will in turn raise your post count with 1 thus no longer being a newbie and now being able to post without restrictions.
For the spammers however, this is all bad news. And that's because their garbage will not make it into the open even if akismet fails (which since I installed it it did not).
Also, in order to not keep unnecessary spammer accounts registered, I will implement a script that will periodically delete all newbie accounts that are not confirmed. And the news here is that all newbie accounts will be reverted to not confirmed periodically and re-sent the confirmation email. Hopefully I'll have time to make that script this year.