生成网站map有什么简易的方法吗

<br /><?PHP<br />$content='<?xml version="1.0" encoding="UTF-8"?><br /><urlset<br />    xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"<br />    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"<br />    xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9<br />       http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd"><br />';<br />$data_array=array(<br />    array(<br />		'loc'=>'http://www.phpernote.com/',<br />		'priority'=>'1.0',<br />		'lastmod'=>'2012-06-03T04:20:32-08:00',<br />		'changefreq'=>'always'<br />    ),<br />    array(<br />		'loc'=>'http://www.phpernote.com/',<br />		'priority'=>'0.5',<br />		'lastmod'=>'2012-06-03T04:20:32-08:00',<br />		'changefreq'=>'daily'<br />    )<br />);<br />foreach($data_array as $data){<br />	$content.=create_item($data);<br />}<br />$content.='</urlset>';<br />$fp=fopen('sitemap.xml','w+');<br />fwrite($fp,$content);<br />fclose($fp);<br /><br />function create_item($data){<br />    $item="<url>\n";<br />    $item.="<loc>".$data['loc']."</loc>\n";<br />    $item.="<priority>".$data['priority']."</priority>\n";<br />    $item.="<lastmod>".$data['lastmod']."</lastmod>\n";<br />	$item.="<changefreq>".$data['changefreq']."</changefreq>\n";<br />    $item.="</url>\n";<br />    return $item;<br />}<br />