Update Services are tools you can use to let other people know you’ve updated your blog. WordPress automatically notifies popular Update Services that you’ve updated your blog by sending a XML-RPC ping each time you create or update a post. In turn, Update Services process the ping and updates their proprietary indices with your update. Now people browsing sites like Technorati or Sphere can find your most recent posts!

http://codex.wordpress.org/Update_Services

WP 主動通知搜尋引擎發新文章。

http://rpc.technorati.com/rpc/ping
http://blogsearch.google.com/ping/RPC2
http://ping.feedburner.com
http://services.newsgator.com/ngws/xmlrpcping.aspx
http://api.my.yahoo.com/RPC2
http://api.my.yahoo.com/rss/ping
http://rpc.pingomatic.com
http://ping.feedburner.com