Disable Comments
I don’t know about your blog but most of the spam comments that roll in are usually given to older posts. In the case of this blog, two posts in particular have drawn spam like flowers attract bees.
The nofollow tag is a tag that I used to have enableddisabled. This allowed a direct link to your site from my site from every comment post. It was one way to reward great comments. However, the spammers troll for this plugin and when they find it, they too make comments hoping to pick up a link from a mid-level ranking site. So I get to delete these regularly.
I’ve deleted the nofollowdofollow plugin so it no longer works. And I’ve disabled comments on the posts that usually draws spammers.
If you find that spammers tend to make comments on old posts, you can do the same thing. Simply disable comments on that individual post. I don’t know if you can do this on other blogging software but with WordPress, the disable comments for this post box is at the bottom of each post. You can disable individual post comments without having to disable all comments on your blog.
But you can still make comments on other posts on my site. Just not the old ones the spammers tend to love.
photocredit
Do you mean the dofollow plugin?
My site is dofollow and it does attract a bit of Spam but Akismet seems to take care of it.
@Mr.Dirty Boots -
That and the forum posts have been magnets for human spam submissions. Akismet gets the automated ones OK but the human powered ones are the pains in the anatomy (mind you, I guess everybody has to earn a living somehow) 
Yeah, I do – and corrected the text (thanks)
You could always try the WP-Ban plugin. You can ban the ips of common spammers whether they are automated or human.
pays to live greens last blog post..Recycling Fabric to Save and Go Green
@pays to live green -
I’ve used this kind of plug-in before, it works “somewhat” but spammers use so many ip’s that it turns into a bit of a game. I run something similar on the forums and it controls the automated stuff (as does Akismet) but not the human related stuff that comes from different ip’s. Frankly, it is what it is – I understand somebody needs to make money doing it – they do it, I id them as spam for Akismet and we both get on with our day. I’m getting used to it and it’s just part of what I do now here and there. Deleting the nofollow plugin made a huge difference to the level of submissions so it’s really all good.