Heres a quick jQuery function to change all incidences of a particular email address on a page into a clickable link.
Useful for things like Terms & Conditions pages where clients will be adding their email adddress multiple times:
<script type="text/javascript">
$(document).ready(function() {
var thePage = $("body");
thePage.html(thePage.html().replace(/info@somewhere.co.uk/ig, '<a href="mailto:info@somewhere.co.uk">info@somewhere.co.uk</a>'));
});
</script>