Movable Type allows you to easily publicize your blog by pinging Weblogs.com, blo.gs, and Technorati with each post. Movable Type administrators should view these three built-in services as default options that can be easily changed for each Movable Type installation.
Think of the three checkboxes above as three variables: BlogsPingURL, WeblogsPingURL, and TechnoratiPingURL. These variables can be overridden in your Movable Type configuration file (mt.cfg) by adding a line with the variable name and value. Each replacement server must be a valid XML–RPC ping beacon similar to Weblogs.com.
Adding the line above to your mt.cfg file will send a ping to Ping-o-Matic instead of blo.gs when the first option is selected.
Now you just need to change the text next to the first option so users are not confused. You will find the weblog preferences page at /tmpl/cms/cfg_prefs.tmpl starting at line 241 in Movable Type 3.16.
Why not just list the other ping beacon in the “Others” box? You can only set other ping beacons to notify on a per-weblog basis and once the data exists each ping beacon listed will receive a notification. It’s better to let your users have the option of turning on or off their pings, but you can choose your own set that best suits your users’ needs. If you are running a service for podcasters you might choose to ping audio.weblogs.com instead of weblogs.com as one option. Or if you are deploying within a firewall you might have your own internal ping beacon for updates. Either way, the choice is yours.