Windows live writer has a cool feature of sending pings to various web directories. Whenever you will publish a new post, windows live writer will send ping to your provided list of servers. Hence they would know about your new contents.
To use this feature go to tools menu of windows live writer. Click on options > Ping Servers. Enable this feature and enter the URLs of ping servers. Following is a list of ping server which i found from a site.
http://rpc.blogrolling.com/pinger/
http://rpc.technorati.com/rpc/ping
http://rpc.weblogs.com/RPC2
http://api.my.yahoo.com/RPC2
http://services.newsgator.com/ngws/xmlrpcping.aspx
http://api.moreover.com/RPC2
http://www.blogpeople.net/servlet/weblogUpdates
http://bblog.com/ping.php
http://ping.feedburner.com/
http://ping.syndic8.com/xmlrpc.php
http://blogsearch.google.com/ping/RPC2
http://rpc.icerocket.com:10080/
http://rpc.pingomatic.com/
http://blogsearch.google.com/ping/RPC2
http://xmlrpc.bloggernetz.de/RPC2
http://bblog.com/ping.php
http://blog.goo.ne.jp/XMLRPC
http://api.my.yahoo.co.jp/RPC2
http://xping.pubsub.com/ping/
http://rpc.reader.livedoor.com/ping
http://ping.wordblog.de/
http://api.moreover.com/RPC2
http://blogsearch.google.at/ping/RPC2
http://ping.weblogalot.com/rpc.php
http://ping.bloggers.jp/rpc/
http://blogsearch.google.de/ping/RPC2
http://ping.namaan.net/rpc
http://rpc.technorati.jp/rpc/ping
http://zhuaxia.com/rpc/server.php
http://www.bloglines.com/ping
http://rpc.bloggerei.de/ping/
After entering above URLs click on Apply and OK. Its set now to ping. See a screenshot below: