Installed Simon Fell's  pingback-client for Radio. Testing pingback... using a previous post...pingback this... pingback Sam Ruby.
Update: worked! This entry appeared on Simon's Pingback Status page! Mwoohahaha! Nice going Simon!
Update: Created a pingback-server using usefulinc.com's XML-RPC classes for PHP, so my posts are now pingback-enabled.
Just checking whether pingback still works. Ok, it does.