most usefull plugins for Wordpress

[Bob Crain]

What are the most usefull plugins for Wordpress blogs?

[AaronSOLD]

Akismet - automated spam filtering
Google Sitemaps - creating & submitting sitemaps
Related Posts - Returns a list of the related entries based on active/passive keyword matches
Wordpress database backup - On-demand backup of your WordPress database

For Options-Writing-Update services, I have the following URLs for pinging:
http://rpc.pingomatic.com/
http://1470.net/api/ping
http://api.feedster.com/ping
http://api.feedster.com/ping.php
http://api.moreover.com/ping
http://api.moreover.com/RPC2
http://api.my.yahoo.com/RPC2
http://api.my.yahoo.com/rss/ping
http://bblog.com/ping.php
http://bitacoras.net/ping
http://blogdb.jp/xmlrpc
http://blog.goo.ne.jp/XMLRPC
http://blogmatcher.com/u.php
http://bulkfeeds.net/rpc
http://coreblog.org/ping/
http://mod-pubsub.org/kn_apps/blogchatt
https://phobos.apple.com/WebObjects/...wa/pingPodcast
http://ping.amagle.com/
http://ping.bitacoras.com
http://ping.bloggers.jp/rpc/
http://ping.blogmura.jp/rpc/
http://ping.blo.gs/
http://ping.cocolog-nifty.com/xmlrpc
http://pinger.blogflux.com/rpc/
http://ping.exblog.jp/xmlrpc
http://ping.feedburner.com
http://ping.myblog.jp
http://pingqueue.com/rpc/
http://ping.blogg.de/
http://ping.rootblog.com/rpc.php
http://ping.syndic8.com/xmlrpc.php
http://ping.weblogalot.com/rpc.php
http://ping.weblogs.se/
http://rcs.datashed.net/RPC2/
http://rpc.blogbuzzmachine.com/RPC2
http://rpc.blogrolling.com/pinger/
http://rpc.britblog.com/
http://rpc.icerocket.com:10080/
http://rpc.newsgator.com/
http://rpc.pingomatic.com/
http://rpc.tailrank.com/feedburner/RPC2
http://rpc.technorati.com/rpc/ping
http://rpc.weblogs.com/RPC2
http://rpc.wpkeys.com/
http://services.newsgator.com/ngws/xmlrpcping.aspx
http://signup.alerts.msn.com/alerts-...ngExtended.doz
http://topicexchange.com/RPC2
http://trackback.bakeinu.jp/bakeping.php
http://www.a2b.cc/setloc/bp.a2b
http://www.bitacoles.net/ping.php
http://www.blogdigger.com/RPC2
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://www.holycowdude.com/rpc/ping/
http://www.lasermemory.com/lsrpc/
http://www.imblogs.net/ping/
http://www.mod-pubsub.org/kn_apps/blogchatter/ping.php
http://www.newsisfree.com/RPCCloud
http://www.newsisfree.com/xmlrpctest.php
http://www.popdex.com/addsite.php
http://www.rssfwd.com/xmlrpc/api
http://www.snipsnap.org/RPC2
http://www.weblogues.com/RPC/
http://xmlrpc.blogg.de
http://xping.pubsub.com/ping/

[fourthring]

I like the flikr plugin from tan tan. It's an easy way to get your photos into your word press blog. Haven't tried the google sitemaps one yet and will give it a try.