Construct Query String
<?php
$url = 'http://xml.amazon.com/onca/xml3?';

$params = array('ManufacturerSearch' => 'oxo',
                'mode'               => 'kitchen',
                'page'               => 1,
                'type'               => 'lite',
                'f'                  => 'xml',
                't'                  => 'trachtenberg-20',
                'dev-t'              => 'XXXXXXXXXXXXXX',
               );
foreach ($params as $a => $v) {
  $url .= "$a=$v&";
}
?>
Use cURL to make get request
<?php
$c = curl_init($url);
curl_setopt($c, CURLOPT_RETURNTRANSFER, 1);
$hits = curl_exec($c);
curl_close($c); 
?>