Mr. "MaxBlogPress Pinger guy" doesn't seem to be out to make enemies, and the plugin does contain some useful ping links. However, the requirements he's using to access his plugin do not fit well into the WordPress community. Things here are free without obligation and permission-based rewards are given out of benevolence to the best plugin creators.
I registered once, then copy/paste the blog ping list to our other blogs.
To Mr. MaxBogPress Pinger guy: congrats on writing a decent plugin - but if you really want it to take off (and it would) remove the email requirement. Best Regards.