Hide Login is a plugin for WordPress by mohammad hossein aghanabi which allows you to create custom URLs for logging in, logging out, administration and registering for your WordPress blog. Instead of advertising your login url on your homepage, you can create a url of your choice that can be easier to remember than wp-login.php, for example you could set your login url to http://www.myblog.com/login for an easy way to login to your website.
You could also enable “Hide Mode” which will prevent users from being able to access ‘wp-login.php’ directly. You can then set your login url to something more cryptic. This won’t secure your website perfectly, but if someone does manage to crack your password, it can make it difficult for them to find where to actually login. This also prevents any bots that are used for malicious intents from accessing your wp-login.php file and attempting to break in.
Download: http://wordpress.org/extend/plugins/hide-login/