I've started noticing stars in my Google Results on reviewed places, products, etc. They look like this:
It seems obvious that these would improve click-thru rates on a search result, so I went on a little search to find out how to include these on my sites.
Google allows these star ratings on review-type sites only. I suspect you may be able to extend it to newspapers or blogs if you had people rating the articles, but I suspect Google must be using some type of system to avoid letting people put 5 star ratings on all of their content.
The process of adding this to your pages is surprisingly simple. You just have to acquaint yourself with microdata and add a bit of code to each page. An example looks like this for the pizza shop:
<div itemscope itemtype="http://data-vocabulary.org/Review-aggregate">
<span itemprop="itemreviewed">L’Amourita Pizza</span>
<span itemprop="rating" itemscope itemtype="http://data-vocabulary.org/Rating">
out of <span itemprop="best">10</span>
based on <span itemprop="votes">24</span> ratings.
<span itemprop="count">5</span> user reviews.
And if you are into this sorta thing, I've also noticed a coupon site doing something similar but adding a 'Map This' line to their results. See here:
Published by: Bradley in rich snippets in seo