Wordpress Periods / Dots in Title / Slug / URL

wp-plugin-periods-in-title.php

<?php
/*
Plugin Name: Periods in Title
Version: 1.0
Description: Allows periods to appear in post/category URIs
Author: Mark Jaquith
Plugin URI: http://txfx.net/code/wordpress/periods-in-titles/
Author URI: http://txfx.net/
*/

remove_filter('sanitize_title', 'sanitize_title_with_dashes');

function sanitize_title_with_dots_and_dashes($title) {
        $title = strip_tags($title);
        // Preserve escaped octets.
        $title = preg_replace('|%([a-fA-F0-9][a-fA-F0-9])|', '---$1---', $title);
        // Remove percent signs that are not part of an octet.
        $title = str_replace('%', '', $title);
        // Restore octets.
        $title = preg_replace('|---([a-fA-F0-9][a-fA-F0-9])---|', '%$1', $title);

        $title = remove_accents($title);
        if (seems_utf8($title)) {
                if (function_exists('mb_strtolower')) {
                        $title = mb_strtolower($title, 'UTF-8');
                }
                $title = utf8_uri_encode($title);
        }

        $title = strtolower($title);
        $title = preg_replace('/&.+?;/', '', $title); // kill entities
        $title = preg_replace('/[^%a-z0-9 ._-]/', '', $title);
        $title = preg_replace('/\s+/', '-', $title);
        $title = preg_replace('|-+|', '-', $title);
        $title = trim($title, '-');
        $title = str_replace('-.-', '.', $title);
        $title = str_replace('-.', '.', $title);
        $title = str_replace('.-', '.', $title);
        $title = preg_replace('|([^.])\.$|', '$1', $title);
        $title = trim($title, '-'); // yes, again

        return $title;
}

add_filter('sanitize_title', 'sanitize_title_with_dots_and_dashes');
?>

Thanks, worked perfectly!