Google free blogging platform “Blogger or Blogspot” doesn't encourage comments and communities, but it's interesting to see who comments on your blog more frequently. This information can be obtained from Blogger's comment feeds, but you need a tool for processing feeds.
Yahoo Pipes is probably the best way to combine, sort, filter and modify feeds. You can use this pipe to list your top commenters for Blogger. While much work has been done for WordPress, you might not find any ready widget for blogger. Inspired by this Yahoo Pipe, you can enter the URL of your blog and the number of top commentators, but the list is not generated instantaneously since Yahoo Pipe must fetch and process at most 10 GData feeds (Blogger's API doesn't include more than 500 comments in a single feed). The pipe could also be used to add the list of top commentators to the blog, using the JSON code generated by Yahoo.
Depending on the number of comments from your blog, the list may not be very meaningful. For example, if your posts get an average of 500 comments, this list will only reflect the hierarchy for the last 10 posts. To see the total number of comments from your blog, open this feed: http://BLOGNAME.blogspot.com/feeds/comments/default (replace BLOGNAME with the proper subdomain), view the page's source and search for "openSearch:totalResults".
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