reprint - 1:59 pm on Oct 1, 2008 (gmt 0)

I am using akismet and havent had a problem with deleted legitimate comments so far. hashcash sounds interesting. I am concerned about JS being turned off and if someone will turn it on to make a comment. They would have to be pretty motivated to make a comment. What about cell phones? I have a couple of sites that visitors use cellphones to make comments. Will hashcash work for them?

As for captcha, will never use it. too much work for the user and puts them off and for the reasons you gave about readability