On your WordPress blog, 

Go to Settings --> Writing

and in the section marked "Update Services" paste these (list below) into the box

and then "Save Changes"

http://ping.syndic8.com/xmlrpc.php
http://rpc.technorati.com/rpc/ping
http://rpc.twingly.com
http://api.moreover.com/RPC2
http://api.moreover.com/ping
http://www.blogdigger.com/RPC2
http://www.blogshares.com/rpc.php
http://www.blogsnow.com/ping
http://ping.syndic8.com/xmlrpc.php
http://rpc.weblogs.com/RPC2
http://www.pingmyblog.com
http://geourl.org/ping
http://rpc.pingomatic.com/
http://ping.blo.gs/
http://ping.feedburner.com
http://api.my.yahoo.co.jp/RPC2
http://audiorpc.weblogs.com/RPC2
http://bblog.com/ping.php
http://bing.com/webmaster/ping.aspx
http://blo.gs/ping.php
http://blog.goo.ne.jp
http://blog.goo.ne.jp/XMLRPC
http://blog.iask.com/rpc2
http://blog.with2.net/ping.php
http://blogpeople.net/ping
http://blogpeople.net/servlet/weblogUpdates
http://blogping.unidatum.com/RPC2
http://blogpingr.de/ping/rpc2
http://blogroots.com
http://blogs.yandex.ru
http://blogsdominicanos.com/ping
http://blogsearch.google.ae/ping/RPC2
http://blogsearch.google.at/ping/RPC2
http://blogsearch.google.be/ping/RPC2
http://blogsearch.google.bg/ping/RPC2
http://blogsearch.google.ca/ping/RPC2
http://blogsearch.google.ch/ping/RPC2
http://blogsearch.google.cl/ping/RPC2
http://blogsearch.google.co.cr/ping/RPC2
http://blogsearch.google.co.hu/ping/RPC2
http://blogsearch.google.co.id/ping/RPC2
http://blogsearch.google.co.il/ping/RPC2
http://blogsearch.google.co.in/ping/RPC2
http://blogsearch.google.co.it/ping/RPC2
http://blogsearch.google.co.jp/ping/RPC2
http://blogsearch.google.co.ma/ping/RPC2
http://blogsearch.google.co.nz/ping/RPC2
http://blogsearch.google.co.th/ping/RPC2
http://blogsearch.google.co.uk/ping/RPC2
http://blogsearch.google.co.ve/ping/RPC2
http://blogsearch.google.co.za/ping/RPC2
http://blogsearch.google.com.ar/ping/RPC2
http://blogsearch.google.com.au/ping/RPC2
http://blogsearch.google.com.br/ping/RPC2
http://blogsearch.google.com.co/ping/RPC2
http://blogsearch.google.com.do/ping/RPC2
http://blogsearch.google.com.mx/ping/RPC2
http://blogsearch.google.com.my/ping/RPC2
http://blogsearch.google.com.pe/ping/RPC2
http://blogsearch.google.com.sa/ping/RPC2
http://blogsearch.google.com.sg/ping/RPC2
http://blogsearch.google.com.tr/ping/RPC2
http://blogsearch.google.com.tw/ping/RPC2
http://blogsearch.google.com.ua/ping/RPC2
http://blogsearch.google.com.uy/ping/RPC2
http://blogsearch.google.com.vn/ping/RPC2
http://blogsearch.google.com/ping/RPC2
http://blogsearch.google.de/ping/RPC2
http://blogsearch.google.es/ping/RPC2
http://blogsearch.google.fi/ping/RPC2
http://blogsearch.google.fr/ping/RPC2
http://blogsearch.google.gr/ping/RPC2
http://blogsearch.google.hr/ping/RPC2
http://blogsearch.google.ie/ping/RPC2
http://blogsearch.google.it/ping/RPC2
http://blogsearch.google.jp/ping/RPC2
http://blogsearch.google.lt/ping/RPC2
http://blogsearch.google.lv/ping/rpc2
http://blogsearch.google.nl/ping/RPC2
http://blogsearch.google.pl/ping/RPC2
http://blogsearch.google.pt/ping/RPC2
http://blogsearch.google.ro/ping/RPC2
http://blogsearch.google.ru/ping/RPC2
http://blogsearch.google.se/ping/RPC2
http://blogsearch.google.sk/ping/RPC2
http://blogsearch.google.tw/ping/RPC2
http://blogsearch.google.us/ping/RPC2

Compliments of www.ListenToYourFreedom.com