si, devi cmq implementare l'sdk, per cui ti serve un APP ID

codice:
<div id="fb-root"></div>
<script>
  window.fbAsyncInit = function() {
    // init the FB JS SDK
    FB.init({
      appId      : 'YOUR_APP_ID',                        // App ID from the app dashboard
      status     : true,                                 // Check Facebook Login status
      xfbml      : true                                  // Look for social plugins on the page
    });

    // Additional initialization code such as adding Event Listeners goes here
  };

  // Load the SDK asynchronously
  (function(){
     // If we've already installed the SDK, we're done
     if (document.getElementById('facebook-jssdk')) {return;}

     // Get the first script element, which we'll use to find the parent node
     var firstScriptElement = document.getElementsByTagName('script')[0];

     // Create a new script element and set its id
     var facebookJS = document.createElement('script'); 
     facebookJS.id = 'facebook-jssdk';

     // Set the new script's source to the source of the Facebook JS SDK
     facebookJS.src = '//connect.facebook.net/en_US/all.js';

     // Insert the Facebook JS SDK into the DOM
     firstScriptElement.parentNode.insertBefore(facebookJS, firstScriptElement);
   }());
</script>

e poi mettere il codice dopo il bottone like
codice:
<fb:like href="http://www.sito.it"></fb:like>
<script>
FB.Event.subscribe('edge.create', function(href, widget) 
{
    alert("click sul like button");
});
</script>