Splogs, otherwise known as spam blogs, have become the latest online blight. And while these fake blogs are littering-up the Web there are some ways to fight back, one of which is through a service called SplogSpot. It's a spam blog search engine that tracks splogs. For a little more background see Search Engine Journal.
Looking the recent splogs list you can see there are dozens added every day. They also offer an API allowing their splog database to be queried in case you want to verify the validity of a given blog.
As they say, their service is "All splogs, no blogs!"