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 postsUpdate Services at WordPress.org
Here is an updated list for year 2014:
[php]http://feedburner.google.com/fb/a/pingSubmit?bloglink=http://www.yourdomain.com/
http://ping.blo.gs/?name=example&url=http://example.com/
http://audiorpc.weblogs.com/RPC2
http://bing.com/webmaster/ping.aspx
http://blog.with2.net/ping.php
http://blog.youdao.com/ping/RPC2
http://blogping.unidatum.com/RPC2
http://blogsearch.google.com/ping/RPC2
http://catapings.com/ping.php
http://effbot.org/rpc/ping.cgi
http://news2paper.com/ping
http://ping.bitacoras.com/
http://ping.bloggers.jp/rpc/
http://ping.fc2.com
http://ping.groove-cast.com/ping.php
http://ping.pubsub.com/ping
http://ping.rss.drecom.jp
http://ping.syndic8.com/xmlrpc.php
http://ping.wordblog.de
http://rpc.bloggerei.de/ping/
http://rpc.pingomatic.com/
http://rpc.twingly.com/
http://rpc.weblogs.com/RPC2
http://serenebach.net/rep.cgi
http://services.newsgator.com/ngws/xmlrpcping.aspx
http://wasalive.com/ping/
http://xianguo.com/xmlrpc/ping.php
http://xping.pubsub.com/ping/
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