This will change the output of the log in/out links generated by Wordpress and allows for a pretty log in/out URL.

Pretty WP Login

///// In your .htaccess: /////

RewriteRule ^login$ wp/wp-login.php

///// In your functions file: /////

function wplogin_filter( $url, $path, $orig_scheme ) {
	// The logout link in the admin bar will does not include a direct.
	// So, when you hit wp-login.php, the logout is completed and the page does a redirect to itself with 'loggedout=true' appended
	// This results in a 404 with the new .htaccess rule in place. So, skip this filter on the admin logout link and all is well.
	if( is_admin() )
		return $url;

	$old  = array( "/(wp\/wp-login\.php)/");
	$new  = array( "login");
	return preg_replace( $old, $new, $url, 1);
}
add_filter('site_url',  'wplogin_filter', 10, 3);