Blog Herald has a good post on Understanding Blog and Ping - I’ll leave it to Duncan to explain:
‘The last six months has seen a massive rise in content theft blogs and spam blogs, and there’s one thing these blogs usually have in common, and that’s the whole “Blog and Ping” thing, but if you don’t know what Blog and Ping is, don’t feel bad, because most people don’t.
But before I start a word of advice: don’t do it. Knowing and understanding your enemy is important in formulating ways of overcoming and defeating them. People who create these blogs are leeches who deserve nothing less than being banned from the search engines they so desperately seek to be included in.’
About Darren Rowse
My name is Darren Rowse and I’m a full time Blogger making a living from blogs like 
“People who create these blogs are leeches who deserve nothing less than being banned from the search engines they so desperately seek to be included in”
Right on!
I must just say that Tenchnorati have been very good at removing a couple of such sites that I noticed. An email (and a note saying look this person says the same here on this blog) and the sites were removed the next day.
Ping is good method and extend your blog to the world.