Here is new blog of NotCaptcha script. The last one has beed disabled by GoDaddy hosting =(
So, here you can try NotCaptcha script in action. Just comment this post
Some information about NotCaptcha:
This is the script for defense of your sites from bots (autoregistration, autocomments, autoposting, autosubmit and so on).
A special feature of the script is that user does not have to input any symbols. He just has to chose their correct position (turn them). Now it is quite easy to enter captcha, but bots can’t do this.
However, it is better to try it – try add comment.
Do not do antispam like this Crazy Captcha
Download NotCaptcha for wordpress from WordPress Plugin Directory