$(function() {
    //set the starting bigestHeight variable
    var biggestHeight = 0;
    //check each of them
    $('.kolom').each(function() {
         //if the height of the current element is
         //bigger then the current biggestHeight value
         if($(this).height() > biggestHeight) {
         //update the biggestHeight with the
         //height of the current elements
              biggestHeight = $(this).height();
         }
    });

    //when checking for biggestHeight is done set that
    //height to all the elements
    $('.kolom').height(biggestHeight);
});

<div id='kolom-sama-tinggi'>
    <div class='kolom'> ... </div>
    <div class='kolom'> ... </div>
    <div class='kolom'> ... </div>
    <div class='kolom'> ... </div>
    <div style='clear:both;'></div>
</div>