BlogCode.com
It sounds like a coding you’d just put on your site, right? But it’s not! In reality, it is a site dedicated to getting user input to sort out a social network (of sorts) to organize blogs into similar groups. It’s not that they’re all writing about the same subjects or with a completely similar tones. It’s really about finding ones that are similar enough that you might enjoy them. For example, I write lots of personal stuff. You could go to my Blog Recommendations page and the system tells you what other blogs you might enjoy. On the other hand, this works with participation. So, if you would like more accurate results, go code my blog (it’s three simple pages) and viola, the results change ever so slightly. 
It’s a great idea that deserves more press. I’m going to be going through and coding at least one blog a day for the month of March. I might do more, we’ll have to see.