I was concerned about the fact that my hosting company doesn't support xml-rpc, although they do support PEAR. So, I contacted Daniel and he responded promptly to inform me that the BlogPing plugin requires PEAR. With this good news I installed the plugin, followed the instructions, and after saving an article in the chosen section, Voila! -- there was a message on the screen informing me that pings were being forwarded to a number of services.
Thanks Daniel for a plugin that is straightforward, and works!