$xmlData =
"<media_gallery> 
<image1>http://www.site.com/resim.jpg</image1> 
<image2>http://www.site.com/resim.jpg</image2> 
<image3>http://www.site.com/resim.jpg</image3> 
</media_gallery>";

$xml = simplexml_load_string($xmlData);

foreach ($xml as $resim) {
	echo $resim."<br />\n";
}