When it comes to pinging RCP and RCP2 update services, I always prefer to ping Ping-o-Matic, because it simply is the best one out there. With one ping, Ping-o-Matic will notify sixteen of the most popular update services. Unfortunately, Ping-o-Matic has become rather unstable over the past month and has been experience several extended periods of downtime. If you ever find Ping-o-Matic to be offline before making a new post on your blog, don’t fret. Elliot Back has posted a comprehensive list of 56 RPC and RPC2 update services.