BT Captcha - simple, Bilingual, Flexible, Protect Your WP Blog Against Comment Spams
AntiBot Captcha - simple good-looking, but well-protected plugin against spam robots for your blog comments
iRobots.txt SEO is a SEO optimized, secure and customizable robots.txt virtual file creator.
PC Robots.txt automatically creates a virtual robots.txt file for your blog. Your robots.txt file can be easily edited from the plugin settings page.
RSS link for this tag.