Proof of concept Toggl API MultiRequest to load currently running timers.

gistfile1.php

<?php
/**
 * Perform a multi-request to the Toggl API
 * @param  String $url    The API URL you are requesting
 * @param  String $method HTTP Request Method (should be 'GET')
 * @param  Array  $tokens An array of Toggl API Tokens and names
 * @return Array          An array of Time Entries
 */
function multiRequest($url, $method, $tokens) {

  // array of curl handles
  $curly = array();
  // data to be returned
  $result = array();

  // multi handle
  $mh = curl_multi_init();

  // loop through $tokens and create curl handles
  // then add them to the multi-handle

  $apiurl    = 'https://www.toggl.com/api/v8/';
  $url = $apiurl.$url;

  foreach ($tokens as $token => $name) {

    $curly[$name] = curl_init();

    curl_setopt($curly[$name], CURLOPT_HTTPAUTH, CURLAUTH_BASIC ) ;
    curl_setopt($curly[$name], CURLOPT_USERPWD, $token.":api_token");
    curl_setopt($curly[$name], CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curly[$name], CURLOPT_SSL_VERIFYPEER, FALSE); // Needed since Toggl's SSL fails without this.
    curl_setopt($curly[$name], CURLOPT_USERAGENT, "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)");
    curl_setopt($curly[$name], CURLOPT_CUSTOMREQUEST, $method);

    curl_setopt($curly[$name], CURLOPT_URL,            $url);

    curl_multi_add_handle($mh, $curly[$name]);
  }

  // execute the handles
  $running = null;
  do {
    curl_multi_exec($mh, $running);
  } while($running > 0);


  // get content and remove handles
  foreach($curly as $name => $c) {
    $output = curl_multi_getcontent($c);
    $output = json_decode('['.$output.']',true);
    if(isset($output[0]) && $output[0] && count($output[0]) > 0) {
      $result[$name] = $output[0];
    }
    curl_multi_remove_handle($mh, $c);
  }

  // all done
  curl_multi_close($mh);

  return $result;
}

function getProjects() {
  $projects = array();
  /* Get a list of all Toggl Projects indexed by Toggl ID.
  Either do this via the API or a local database of Projects.
  */
  $projects[12345] = 'Website Build Project';
  $projects[98765] = 'Website Design Project';
  return $projects;
}

/* Helper function to convert a duration in seconds into HH:MM:SS */
function getDuration($duration) {
  $duration = time() + $duration; // Seconds
  return gmdate("H:i:s", $duration);
}

/* The Toggl API URL */
$start = urlencode(date('c',strtotime('today')));
$end   = urlencode(date('c',strtotime('tomorrow')));
$url   = "time_entries?start_date={$start}&end_date={$end}";

/* Toggl API Tokens */
$tokens = array();
$tokens['abcdefghijklmnopqrstuvwxyz'] = 'John Smith';
$tokens['12345678901234567890123456'] = 'Chris Atomix';


/* Perform the Request */
$toggltimes = multiRequest($url, 'GET', $tokens);
$timers = array();

$projects = getProjects(); // A list of Projects

foreach($tokens as $token=>$name) {

  $timer             = array();
  $timer['name']     = $name;
  $timer['duration'] = '&nbsp;';
  $timer['summary']  = '(No Timer Running)';
  $timer['project']  = '&nbsp;';
  $timer['running']  = false;

  $times = $toggltimes[$name];

  if($times && count($times) > 0) {

    foreach($times as $time) {

      if($time['duration'] < 0) {
        // Currently running
        $timer['duration'] = getDuration($time['duration']);
        $timer['summary'] = (!empty($time['description'])) ? $time['description'] : '(No Description)';
        $timer['running'] = true;
        $timer['project'] = '(No Project Selected)';
        if($time['pid'] > 0 && isset($projects[$time['pid']])) {
          $timer['project'] = $projects[$time['pid']];
        }
      }
    }
  }
  $timers[] = $timer;
}

/* Now build the HTML with the $timers array however you want */

Please never never never ever use this line on a live website:
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);

If that line is needed in order to make a script work, fix it, instead of breaking security!! If your key doesn't fit your front door anymore, you fix the lock, you don't leave the door open all day. Just like that, you should fix the security on this issue as well.

It is very simple:

• Get a copy of a up-to-date ca certificates bundle. You can get this from any modern Linux distribution, as well as from Mozilla and from the WordPress installation package.
• Put the file in your directory
• Refer to it using curl_setopt( $ch, CURLOPT_CAINFO, "insert-filename-here');
  A good example is included in WordPresses wp-includes/class-http.php line 1411.

(Also, curl connects perfectly from my server. If you get yourself a up-to-date webserver, this wouldn't be an issue in the first place.)