Dan Grossman has released a review plug-in that allows you to collect reviews or ratings on just about anything. A pretty cool and powerful little plug-in system.
The DG Review Site (DGRS) plugin for WordPress allows you to turn your blog into a powerful review engine. It’s flexible in design and presentation so you could use it as an additional interaction feature for your blog to collect reviews of your posts, or to drive a product/service review site where your users contribute the reviews.
Some of the features include being able to collect ratings on posts with comments, define what categories you want to collect ratings for, and display them in pretty much any way you want to.
If you are looking at finding out what your readership likes or doesn’t like in regards to the content or opinions on your blog, this might be a plug-in to check out.