Probably by installing the "generic ping plugin" and providing it with the info it asks for on it's settings page, but I haven't actually used it. Just looked at the file a bit and guess this is how you will want to go.

Does ping-o-matic not ping the service you wish to ping?

Hey, Ed! There's one it doesn't. No big deal. I'll try it out, thanks.

It's pretty easy. What's the service that you want to ping?

I'd like to ping Twingly http://www.twingly.com/ which is used by many newspapers in Scandinavia but I couldn't make it work (neither manually nor via the generic ping plugin

According to http://rpc.twingly.com/ , the service uses the weblogsAPI, so the generic ping plugin should work.

After installing the plugin and set the url to http://rpc.twingly.com/, have you added the new ping service to your blog?

Theoretically yes, but links to my blog did not show up on the newspapers website last time I tried, so something must have gone wrong

Well, I've tried do add the twingly on my blog but get a error:

# Pingando twingly...
# Erro remoto: Method takes parameters and there is incorrect number of param elements. (-1)

I will research.

# Pingando twingly...
# Resposta: [] [Thanks for the ping.]

The configs (screenshot):
http://b2evolution.waltercruz.com/twingly.png

After add that, you have to go in the blog settings and select twingly to ping.

Pinging twingly...
Response: [0] [Thanks for the ping.]

Done.

Thanks a lot for the instructions. The screenshot was useful as well. Now, twingly shows up in the blog settings. Thanks!

Nevertheless, twingly didn't pick up my post and showed it here http://www.twingly.no/search.aspx?s=link:http://www.dagbladet.no/kultur/2008/03/12/529494.html

All blog posts that link to http://www.dagbladet.no/kultur/2008/03/12/529494.html should be displayed there. Strange

If you want to ping, say, 5 services, do you have to install the generic ping 5 times?
Does it work only for the URI format rpc.xxx.xxx or for other format?

I found a recent list of services that can be pinged and although I don't want to ping all of them, I am wondering what is the most efficient way to use the generic ping plugin?

http://blogsearch.google.com/ping/RPC2
http://1470.net/api/ping
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://bblog.com/ping.php
http://bitacoras.net/ping
http://blog.goo.ne.jp/XMLRPC
http://blogdb.jp/xmlrpc
http://blogmatcher.com/u.php
http://bulkfeeds.net/rpc
http://coreblog.org/ping/
http://mod-pubsub.org/kn_apps/blogchatt
http://www.lasermemory.com/lsrpc/
http://ping.amagle.com/
http://ping.bitacoras.com
http://ping.blo.gs/
http://ping.bloggers.jp/rpc/
http://ping.cocolog-nifty.com/xmlrpc
http://ping.blogmura.jp/rpc/
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://rcs.datashed.net/RPC2/
http://rpc.blogbuzzmachine.com/RPC2
http://rpc.blogrolling.com/pinger/
http://rpc.icerocket.com:10080/
http://rpc.newsgator.com/
http://rpc.pingomatic.com
http://rpc.technorati.com/rpc/ping
http://rpc.weblogs.com/RPC2
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.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.snipsnap.org/RPC2
http://www.weblogues.com/RPC/
http://xmlrpc.blogg.de
http://xping.pubsub.com/ping/

Speaking of which, I installed the generic ping plugin with the twingly URI, just for test in the general parameters tab. Do I have to do something in my blog?
What will trigger the pluggin call when I publish a new article?