DZone released voting scripts which allows site visitors to vote from the site itself. You can find voting widgets for Wordpress as well as for Jroller, but nothing for blogger :(.
So here's simplest way to add it to your Blogger blog, Just copy/paste lines below to your Blogger HTML template (after expanding widget templates):
<div style='float:right; margin-left:10px;'>
<script type='text/javascript'>var dzone_url = '<data:post.url/>'</script>
<script type='text/javascript'>var dzone_title = '<data:post.title/>'</script>
<script type='text/javascript'>var dzone_style = 1</script>
<script language='javascript' src='http://widgets.dzone.com/widgets/zoneit.js'/>
</div>
right before
<p><data:post.body/></p>
Here's the image screen shot:
Click on it to enlarge. You might want to customize it a bit, just try out different div styles. Developers, Keep voting!