Folks who read papers like the Washington Post online are familar with the Who’s Blogging feature powered by the blog search engine Technorati. Basically, Who’s Blogging allows you to view a list of blog entries linking to the Post story you are reading. You can see an example of this in action on pretty much any Post story.

I saw on Techcrunch that the new blog search engine Sphere has launched a competing tool that is currently getting a trial on Time Magazine’s website. According to Sphere, the Sphere tool is different in that it performs a semantic analysis of web pages to find articles on the same topic. So, in theory, the new Sphere tool will find more related blog entries than the Technorati product since it is searching based on similarities in content between the article and blog entries as opposed to simply whether the blog entry links to the article.

Below is an example of Sphere tool in action.

Frankly, I’m not sure which approach is best. If I’m reading a sports column by Michael Wilbon about the Yankees-Red Sox series, there is a decent chance I only want to read blog entries on that very specific column and not the series in general. However, if I’m reading a straight news story from the Post on immigration, I’m probably interested in seeing all related blog entries. I don’t know.

Either way, Time Magazine’s experimentation with Sphere is another step forward in the melding of traditional newspaper and consumer generated content.