http://loveandtheft.org/2008/09/19/styled-checkboxes-and-radiobuttons-with-jquery/
No tweaks needed, just copy the images and the js and include this in
the layout.html
<script src="http://totmacher.eu/jquery/radio/src/
jquery.checkize.js"></script>
<script>
images = {
checked:"{{=URL(r=request,c='static',f='images/
checked.gif')}}",
unchecked:"{{=URL(r=request,c='static',f='images/
unchecked.gif')}}"
};
$(document).ready(function() {
$("input[@type=checkbox]").checkize(images);
$("input[@type=radio]").radize(images);
});
</script>