I was looking through the WordPress admin screens, and found that it ‘pings’ http://rpc.pingomatic.com/ each time you update/add an article.
So, being the curious sort, I looked into this and found that it’s really and open input to update your Blog listing in several search engines.
To manually submit, you can fill in and submit the form available at http://pingomatic.com/.
They also have a Blog of their own at http://pingomatic.wordpress.com/.
