$urls=array("http://google.com","http://yahoo.com"); // could be thousands in this list

  $mh = curl_multi_init();

  // create queue of curl handles
  $handles=array();
  $mh=curl_multi_setup_queue($urls,$handles);


  // execute requests
  curl_multi_perform($mh);

  // fetch data
  $data=array(); $failed=array();
  curl_multi_data($mh,$handles,$data,$failed);

  foreach($data as $content) {
    if(isset($failed[$i])) {
      echo "ERROR $failed[$i]\n";
      continue;
    }
    echo "$content\n";
  }

/ * FUNCTIONS */
function curl_multi_setup_queue($urls,&$c) {
  $mh = curl_multi_init(); if(!$mh) die("CANT GET MULTIHANDLE\n");
  // create work queue of curl handles
  $c=array();
  foreach($urls as $i=>$url)
  { $c[$i]=curl_setup($url);
    if(!$c[$i]) {
      err(curl_log_error($c[$i],"curl_setup($url) failed | "));
      continue;
    }
    $rc=curl_multi_add_handle($mh,$c[$i]);
    if($rc!=0) {
      err(curl_log_error($c[$i],"curl_multi_add_handle() failed | $rc | "));
      continue;
    }

  }
  return $mh;

}
function curl_multi_perform(&$mh)
{ if(!$mh) return FALSE;
  // start performing the request
  while(($mrc=CURLM_CALL_MULTI_PERFORM==curl_multi_exec($mh, $active)));

  while ($active and $mrc == CURLM_OK) {
    // wait for network
    if (curl_multi_select($mh) != -1) {
      // read/write all data
      while (($mrc=CURLM_CALL_MULTI_PERFORM==curl_multi_exec($mh, $active)));
    }
  }
  if ($mrc != CURLM_OK) {
    err("Curl multi read error $mrc\n");
  }
  return;
}

function curl_multi_data(&$mh,&$handles,&$data,&$failed)
{ // get data
  foreach ($handles as $i=>$h) {
    // look for err
    $err = curl_error($h);
    if ($err) {
debug("CURL ERROR: $err");
      $e=curl_log_error($h);
      $data[$i]='';
      $failed[$i]=$e;
    }
    else {
      $data[$i]=curl_multi_getcontent($h);
    }
    curl_multi_remove_handle($mh,$h);
    curl_close($h);
  }
  return;
}

function curl_log_error($ch)
{ $r=curl_error($ch);
  return $r;
}