Technorati is a blog search engine, and a powerful social media site.
WordPress Master automatically pings Technorati whenever you publish a new post.
Once you've got your Authority Site up and running, with at least a dozen posts, sign up for a free account with Technorati and claim your blog.
(If you install WPM on subdomains, claim each of those as well because they are separate, independent blogs.)
To claim your blog on Technorati, follow the instructions on their site. The claiming process there can be frustrating and sometimes requires several tries, but don't give up. If your claim doesn't go through right away, check back there regularly to see if your claim has been successful yet, and keep trying.