How to open multiple URLs with cURL without delay

Your solution would be simultaneous cURL HTTP requests.
For faster implementation, you can use this function (thanks to phpied):

function multiRequest($data, $options = array()) {  // array of curl handles  $curly = array();  // data to be returned  $result = array();  // multi handle  $mh = curl_multi_init();  // loop through $data and create curl handles  // then add them to the multi-handle  foreach ($data as $id => $d) {    $curly[$id] = curl_init();    $url = (is_array($d) && !empty($d['url'])) ? $d['url'] : $d;    curl_setopt($curly[$id], CURLOPT_URL,            $url);    curl_setopt($curly[$id], CURLOPT_HEADER,         0);    curl_setopt($curly[$id], CURLOPT_RETURNTRANSFER, 1);    // post?    if (is_array($d)) {      if (!empty($d['post'])) {        curl_setopt($curly[$id], CURLOPT_POST,       1);        curl_setopt($curly[$id], CURLOPT_POSTFIELDS, $d['post']);      }    }    // extra options?    if (!empty($options)) {      curl_setopt_array($curly[$id], $options);    }    curl_multi_add_handle($mh, $curly[$id]);  }  // execute the handles  $running = null;  do {    curl_multi_exec($mh, $running);  } while($running > 0);  // get content and remove handles  foreach($curly as $id => $c) {    $result[$id] = curl_multi_getcontent($c);    curl_multi_remove_handle($mh, $c);  }  // all done  curl_multi_close($mh);  return $result;}

And use it like this:

$data = array(  'http://search.yahooapis.com/VideoSearchService/V1/videoSearch?appid=YahooDemo&query=Pearl+Jam&output=json',  'http://search.yahooapis.com/ImageSearchService/V1/imageSearch?appid=YahooDemo&query=Pearl+Jam&output=json',  'http://search.yahooapis.com/AudioSearchService/V1/artistSearch?appid=YahooDemo&artist=Pearl+Jam&output=json');$r = multiRequest($data);echo '<pre>';print_r($r);

Hope it helps.
Also read this.