Example code showing how to use Drupal API's support for xml rpc to post an item to a blog which supports the metaweblog XML-RPC api:

xmlrpc('http://blogs.www.friendster.com/t/api', 'metaWeblog.newPost', '31337', 'example@example.com', 'sample password', array('title' => 'drupal xmlrpc and metaweblog.newpost tutorial', 'link' => 'http://wtanaka.com/node/7746', 'description' => 'sample code for using xmlrpc and metaweblog.newpost in drupal'));

Note in this example that friendster's XMLRPC API url is blogs.www.friendster.com, not www.blogs.friendster.com as is claimed in some places.