$url = 'http://img.yandex.net/i/www/logo.png';
$path = './images/logo.png';
file_put_contents($path, file_get_contents($url));

$ch = curl_init('http://img.yandex.net/i/www/logo.png');
$fp = fopen('./images/logo.png', 'wb');
curl_setopt($ch, CURLOPT_FILE, $fp);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_exec($ch);
curl_close($ch);
fclose($fp);