Pinging is a very effective method of promotion for blogs that allows you to submit individual blog posts or your blog home page to hundreds or thousands of directories at once.Pinging your blog pages will help the search engines spider all of your blog posts. By doing pinging your blogs will get a very good traffic and it will boost the PageRank and authority of your blog with keywords that relate to your blog posts, boosting your search engine optimization efforts for your blog.
How to post in ping:

1. Enter the title of your page. You should include your keyword in the title.
2. Type the URL of the individual blog post you want to ping.
3. Select a Categot=ry
4. Submit

Here is a list of some of the ping services that accept pings: api.moreover.com/RPC2
api.my.yahoo.co.jp/RPC2
api.my.yahoo.com/RPC2
audiorpc.weblogs.com/RPC2
blog.goo.ne.jp/XMLRPC
blogpeople.net/ping
blogsearch.google.ae/ping/RPC2
blogsearch.google.at/ping/RPC2
blogsearch.google.be/ping/RPC2
blogsearch.google.bg/ping/RPC2
blogsearch.google.ca/ping/RPC2
blogsearch.google.ch/ping/RPC2
blogsearch.google.cl/ping/RPC2
blogsearch.google.co.cr/ping/RPC2
blogsearch.google.co.hu/ping/RPC2
blogsearch.google.co.id/ping/RPC2