Many bloggers use wordpress which can automatically notify one or more servers each time the blogger creates a new post or updates an existing one. Many other blogging platforms will attempt to do the same. For the people who are slightly technologically minded, “the tool sends an XML-RPC signal to one or more “ping servers,” which can then generate a list of blogs that have new material“. - wikipedia.

http://blogsearch.google.com/ping/RPC2
http://api.feedster.com/ping
http://api.moreover.com/ping
http://api.moreover.com/RPC2
http://blog.goo.ne.jp/XMLRPC
http://blogdb.jp/xmlrpc/
http://coreblog.org/ping/
http://ping.blo.gs/
http://ping.bloggers.jp/rpc/
http://ping.cocolog-nifty.com/xmlrpc
http://ping.syndic8.com/xmlrpc.php
http://ping.weblogalot.com/rpc.php
http://pinger.blogflux.com/rpc
http://rpc.blogrolling.com/pinger/
http://rpc.icerocket.com:10080/
http://rpc.pingomatic.com/
http://rpc.technorati.com/rpc/ping
http://rpc.weblogs.com/RPC2
http://topicexchange.com/RPC2
http://www.blogdigger.com/RPC2
http://xping.pubsub.com/ping
http://api.my.yahoo.com/rss/ping
http://rpc.pingomatic.com/
http://1470.net/api/ping
http://www.a2b.cc/setloc/bp.a2b
http://api.feedster.com/ping
http://api.moreover.com/RPC2
http://api.moreover.com/ping
http://api.my.yahoo.com/RPC2
http://api.my.yahoo.com/rss/ping
http://www.bitacoles.net/ping.php
http://bitacoras.net/ping
http://blogdb.jp/xmlrpc
http://www.blogdigger.com/RPC2
http://blogmatcher.com/u.php
http://www.blogoole.com/ping/
http://www.blogoon.net/ping/
http://www.blogpeople.net/servlet/weblogUpdates
http://www.blogroots.com/tb_populi.blog?id=1
http://www.blogshares.com/rpc.php
http://www.blogsnow.com/ping
http://www.blogstreet.com/xrbin/xmlrpc.cgi
http://blog.goo.ne.jp/XMLRPC
http://bulkfeeds.net/rpc
http://coreblog.org/ping/
http://www.lasermemory.com/lsrpc/
http://mod-pubsub.org/kn_apps/blogchatt
http://www.mod-pubsub.org/kn_apps/blogchatter/ping.php
http://www.newsisfree.com/xmlrpctest.php
http://ping.amagle.com/
http://ping.bitacoras.com
http://ping.blo.gs/
http://ping.bloggers.jp/rpc/
http://ping.blogmura.jp/rpc/
http://ping.cocolog-nifty.com/xmlrpc
http://ping.exblog.jp/xmlrpc
http://ping.feedburner.com
http://ping.myblog.jp
http://ping.rootblog.com/rpc.php
http://ping.syndic8.com/xmlrpc.php
http://ping.weblogalot.com/rpc.php
http://ping.weblogs.se/
http://pingoat.com/goat/RPC2
http://www.popdex.com/addsite.php
http://rcs.datashed.net/RPC2/
http://rpc.blogbuzzmachine.com/RPC2
http://rpc.blogrolling.com/pinger/
http://rpc.icerocket.com:10080/
http://rpc.pingomatic.com/
http://rpc.technorati.com/rpc/ping
http://rpc.weblogs.com/RPC2
http://www.snipsnap.org/RPC2
http://trackback.bakeinu.jp/bakeping.php
http://topicexchange.com/RPC2
http://www.weblogues.com/RPC/
http://xping.pubsub.com/ping/
http://xmlrpc.blogg.de/
http://rpc.pingomatic.com/
http://www.a2b.cc/setloc/bp.a2b
http://api.feedster.com/ping
http://api.my.yahoo.com/RPC2
http://api.my.yahoo.com/rss/ping
http://www.blogdigger.com/RPC2
http://www.blogshares.com/rpc.php
http://www.blogsnow.com/ping
http://www.blogstreet.com/xrbin/xmlrpc.cgi
http://coreblog.org/ping/
http://ping.blo.gs/
http://ping.feedburner.com
http://ping.syndic8.com/xmlrpc.php
http://ping.weblogalot.com/rpc.php
http://www.popdex.com/addsite.php
http://rpc.blogrolling.com/pinger/
http://rpc.technorati.com/rpc/ping
http://rpc.weblogs.com/RPC2
http://topicexchange.com/RPC2
http://xping.pubsub.com/ping/
http://api.my.yahoo.com/rss/ping
http://api.moreover.com/ping
http://rpc.icerocket.com:10080/
http://api.feedster.com/ping
http://api.moreover.com/RPC2
http://api.my.yahoo.com/RPC2
http://xping.pubsub.com/ping/
http://ping.blo.gs/
http://ping.feedburner.com
http://ping.syndic8.com/xmlrpc.php
http://ping.weblogalot.com/rpc.php
http://rpc.blogrolling.com/pinger/
http://rpc.icerocket.com:10080/
http://rpc.newsgator.com/
http://rpc.technorati.com/rpc/ping
http://rpc.weblogs.com/RPC2
http://topicexchange.com/RPC2
http://www.blogdigger.com/RPC2
http://www.blogstreet.com/xrbin/xmlrpc.cgi
http://www.newsisfree.com/RPCCloud
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
http://www.wasalive.com/ping/

Some ping servers, have limitations on them as to how often you can ping, but dont worry if you hit the limit every now and then - it happens - especially if you a fast type. However, you should be aware of spamming these engines and it is possible that they could ban you from using their service.

Unfortunately, ping spammers harness the power of the ping servers to create spam blogs which typically scrape content to add to their website. Spam blogs hope to rank well for scraped content and keywords of other users where it is likely that Google Adsense will appear to try and make money of the unsuspecting user.