Installing and using the Disqus (<a href="http://disqus.com/" rel="nofollow">http://disqus.com/</a>) plugin located here: <a href="http://wordpress.org/extend/plugins/disqus-comment-system/" rel="nofollow">http://wordpress.org/extend/plugins/disqus-comment-system/</a> helped a lot on my blog.<p>Additionally you can use the reCaptcha plugin: <a href="http://wordpress.org/extend/plugins/wp-recaptcha/" rel="nofollow">http://wordpress.org/extend/plugins/wp-recaptcha/</a>.<p>Both require you to signup on their respective sites for an API key. Both should help tremendously.