Kailash Nadh: Feedburner launched a pinging service named "PingShot" recently. Its supposed to ping to a number of services, just like Pingoat does, every time you update you feed. But odd enough, they have included certain Ping services like Pingoat, that again ping the same sites Pingshot pings individually.
http://www.pingoat.com/goatlog/post/index/25/Feedburners-PingShot
Randy: PingShot, Pingoat and Pingomatic are blogosphere ping sources, which I'll define as a ping source that pings ping sinks. MHO, one ping source should never ping another ping source or accept a ping from another ping source. Of course, you could devise an algorithm to minimize the damage of redundant pings, but wouldn't it be simpler if you just followed rule #406.
Rule #406: One ping source should never ping another ping source or accept a ping from another ping source.
Randy