Wordpress Security Admin Tools
If you like it, secure and protect it ! particularly your WP.
The plugin “WP Security Scan” is a good one to help secure your WP installation. Click here to download it.
The below is a brief report after its initial scan:
WordPress Version: 2.x You have the latest stable version of WordPress.
Your table prefix should not be wp_. Click here to change it.
Your WordPress version is successfully hidden.
WordPress DB Errors turned off.
No user “admin”.
The file .htaccess does not exist in wp-admin/.
In addition, this page at Weblog Tools Collection has a very good post on “ten security tools for Wordpress”.

I love this site
Matt has one very good post on WP security:
http://ma.tt/2008/04/securityfocus-sql-injection-bogus/#comment-441920
This post list Top 10 security plugins of Wordpress:
http://speckyboy.com/2008/04/08/top-10-security-and-protection-plugins-for-wordpress/
Check it out.