Most anti-comment-spambot-plugins focus on user interaction, e.g. captcha or math comment spam protection. Some use JavaScript and/or Sessions and check each comment against common spam phrases. But you still have to manage some comments. Yawasp focuses on handling comment-spam-protection without these measures. It replaces the names of the comment form fields with random names, protecting your blog from spambots that aim at the default comment field names. Furthermore it adds a blank field, hidden from the user, that needs to be left empty. In addition, the random field names are changed every 24 hours, giving a spambot no chance to adapt to the comment form.

Now the user must no longer fill out any additional fields in the comment form, and you can focus on blogging and your readers comments.

Yawasp is a real lightweight. It does not need JavaScript, Cookies or Sessions, but still is very effective.
Features in a nutshell
Does not require JavaScript, Cookies or Sessions
No extra field for user input
False-positives are impossible
No need to manage comments
Easy installation

for the latest update you can use this page:

http://downloads.wordpress.org/plugin/yawasp.zip

i hope it use full for all of you