Another solution is to overlay a transparent div and add a click event to that div.
Working sample: http://jsfiddle.net/w1ll3m/AxJHH/
<div class="container">
<iframe src="#url"></iframe>
<div class="overlay"></div>
</div>
css to position the div.overlay over the iframe:
.container{position:relative;float:left;}
.overlay{top:0;left:0;width:100%;height:100%;position:absolute;}
Add the event:
$('.overlay').click(function(){alert('hello');});