very extensive and cleaned ping list here:
http://journalxtra.com/2011/05/wordpress-ping-list-updated/

recommends installing CBNet Ping Optimizer
http://wordpress.org/extend/plugins/cbnet-ping-optimizer/

Journal Xtra’s Ping List that i’m using. no Adult Sites:
http://rpc.pingomatic.com
http://ping.weblogs.se/
http://blogmatcher.com/u.php
http://coreblog.org/ping/
http://www.blogpeople.net/servlet/weblogUpdates
http://bulkfeeds.net/rpc
http://trackback.bakeinu.jp/bakeping.php
http://ping.myblog.jp
http://ping.bitacoras.com
http://ping.bloggers.jp/rpc/
http://ping.blogmura.jp/rpc/
http://xmlrpc.blogg.de
http://1470.net/api/ping
http://bblog.com/ping.php
http://blog.goo.ne.jp/XMLRPC

http://rpc.pingomatic.com
http://ping.weblogs.se/
http://blogmatcher.com/u.php
http://coreblog.org/ping/
http://www.blogpeople.net/servlet/weblogUpdates
http://bulkfeeds.net/rpc
http://trackback.bakeinu.jp/bakeping.php
http://ping.myblog.jp
http://ping.bitacoras.com
http://ping.bloggers.jp/rpc/
http://ping.blogmura.jp/rpc/
http://xmlrpc.blogg.de
http://1470.net/api/ping
http://bblog.com/ping.php
http://blog.goo.ne.jp/XMLRPC

If you are having trouble getting a specific page or even en entire website indexed by Google, try these two steps:
1.    Try bringing the site or page up in the Chrome browser.  According to some people working at the big G, Chrome works as a pinging utility for Google.
2.    Post a backlink to your site on Orkut.com  This is a Google owned microblogging platform.  But you aren’t limited to just 140 characters like you are on Twitter, and you can even use html and embed codes.  All of Orkut.com’s pages carry a PR of 8,   Your Kung Fu will be strong with this one…

THE LIST
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.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.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.us/ping/RPC2
http://api.my.yahoo.co.jp/RPC2
http://ping.blogs.yandex.ru/RPC2
http://blog.youdao.com/ping/RPC2

http://audiorpc.weblogs.com/RPC2
http://blo.gs/ping.php
http://blog.with2.net/ping.php
http://blogpeople.net/ping
http://godesigngroup.com/blog/feed
http://ping.blo.gs
http://ping.fc2.com
http://ping.kutsulog.net
http://ping.myblog.jp
http://ping.pubsub.com/ping
http://ping.wordblog.de
http://rpc.aitellu.com
http://rpc.bloggerei.de/ping/
http://rpc.reader.livedoor.com/ping
http://rpc.twingly.com/
http://rpc.weblogs.com/rpc2
http://serenebach.net/rep.cgi
http://services.newsgator.com/ngws/xmlrpcping.aspx
http://sindice.com/xmlrpc/api
http://www.syndic8.com/xmlrpc.php
http://www.zhuaxia.com/rpc/server.php
http://xping.pubsub.com/ping/
http://zhuaxia.com/rpc/server.php

http://ping.feedburner.com
http://rpc.pingomatic.com