Hyper-viligent WP sanitization from PressForward

sanitize.php

/**
 * Sanitize a string for use in URLs and filenames
 *
 * @since 1.7
 * @link http://stackoverflow.com/questions/2668854/sanitizing-strings-to-make-them-url-and-filename-safe
 *
 * @param string $string The string to be sanitized
 * @param bool $force_lowercase True to force all characters to lowercase
 * @param bool $anal True to scrub all non-alphanumeric characters
 * @return string $clean The cleaned string
 */
function pf_sanitize($string, $force_lowercase = true, $anal = false) {
	$strip = array("~", "`", "!", "@", "#", "$", "%", "^", "&", "*", "(", ")", "_", "=", "+", "[", "{", "]",
				   "}", "\\", "|", ";", ":", "\"", "'", "‘", "’", "“", "”", "–", "—",
				   "—", "–", ",", "<", ".", ">", "/", "?");
	if (is_array($string)){
		$string = implode(' ', $string);
	}
	$clean = trim(str_replace($strip, "", strip_tags($string)));
	$clean = preg_replace('/\s+/', "-", $clean);
	$clean = ($anal) ? preg_replace("/[^a-zA-Z0-9]/", "", $clean) : $clean ;
	return ($force_lowercase) ?
		(function_exists('mb_strtolower')) ?
			mb_strtolower($clean, 'UTF-8') :
			strtolower($clean) :
		$clean;
}
/**
 * Create a slug from a string
 *
 * @since 1.7
 * @uses pf_sanitize()
 *
 * @param string $string The string to convert
 * @param bool $case True to force all characters to lowercase
 * @param bool $string True to scrub all non-alphanumeric characters
 * @param bool $spaces False to strip spaces
 * @return string $stringSlug The sanitized slug
 */
function pf_slugger($string, $case = false, $strict = true, $spaces = false){
	if ($spaces == false){
		$string = strip_tags($string);
		$stringArray = explode(' ', $string);
		$stringSlug = '';
		foreach ($stringArray as $stringPart){
			$stringSlug .= ucfirst($stringPart);
		}
		$stringSlug = str_replace('&amp;','&', $stringSlug);
		//$charsToElim = array('?','/','\\');
		$stringSlug = pf_sanitize($stringSlug, $case, $strict);
	} else {
		//$string = strip_tags($string);
		//$stringArray = explode(' ', $string);
		//$stringSlug = '';
		//foreach ($stringArray as $stringPart){
		//	$stringSlug .= ucfirst($stringPart);
		//}
		$stringSlug = str_replace('&amp;','&', $string);
		//$charsToElim = array('?','/','\\');
		$stringSlug = pf_sanitize($stringSlug, $case, $strict);
	}
	return $stringSlug;
}