One option would be to use some jQuery and the timeago plugin: http://timeago.yarp.com/
Your view would need to look something like this:
<script src="jquery.min.js" type="text/javascript"></script>
<script src="jquery.timeago.js" type="text/javascript"></script>
<abbr class="timeago" title="2008-07-17T09:24:17Z">July 17, 2008</abbr>
jQuery(document).ready(function() {
jQuery("abbr.timeago").timeago();
});