[mserega]

function come(elem) {
  var docViewTop = $(window).scrollTop(),
    docViewBottom = docViewTop + $(window).height(),
    elemTop = $(elem).offset().top,
    elemBottom = elemTop + $(elem).height();

  return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
}

onscroll = function(){
if (come("#el")) //запускаем первый;
if (come("#el")) //запускаем второй;
//....
};

А как запуска?

<div class="counter">
 <i class="fa fa-commenting-o fa-5x greencolor"></i>
 <h1 class="timer count-number" data-to="$COMMENTS$" data-speed="2000"></h1>
 <p class="count-text greencolor">Коментарии</p>
 </div>

 <div class="counter">
 <i class="fa fa-picture-o fa-5x greencolor"></i>
 <h1 class="timer count-number" data-to="$PHOTO$" data-speed="4000"></h1>
 <p class="count-text greencolor">Фотографий</p>
 </div> 

 <div class="counter">
 <i class="fa fa-object-group fa-5x greencolor"></i>
 <h1 class="timer count-number" data-to="$BLOG$" data-speed="3000"></h1>
 <p class="count-text greencolor">Блогов</p>
 </div> 

 <div class="counter">
 <i class="fa fa-newspaper-o fa-5x greencolor"></i>
 <h1 class="timer count-number" data-to="$NEWS$" data-speed="2000"></h1>
 <p class="count-text greencolor">Новостей</p>
 </div>