Vitor Carvalho

This plugin is DEAD until further development. 
Don’t use it as this can lead your WordPress instalation into problems.
With this plugin you can change wp-admin and wp-login.php to any of your choice. 
You can have <code>http://example.org/login</code> instead of <code>http://example.org/wp-login.php</code> or <code>http://example.org/admin/</code> instead of <code>http://example.org/wp-admin/</code>
You just need to enter into <code>options-permalink.php</code>page and set the variables. 
After the setup wp-login.php and wp-admin path are not anymore available and you should use the newest onews you set.
This works with Multisite Networks. You can set a default value in Options page of Multisite settings section.
Languages available: English, Português, Español, Italiano, Deutsch.

Custom Login and Admin URLs (CLAU)

AVOID TO USE THIS PLUGIN! Change wp-admin and wp-login URL to any of your choice. Security by obscurity!

cortesfrau

This plugin allows users to enhance the default WP login page.

Better WP Login Page

This plugin allows users to enhance the default WP login page.

Custom Login and Admin URLs (CLAU) vs Better WP Login Page