I have just found a stick of ZZ9 rock I acquired at the Brighton Worldcon in 1987. It really hasn't lasted that well, let's just say I won't be bringing it to the AGM. I only hope that was the last of them now.
The bad news is that we are close to melting in our tiny, non-airconditioned office. The good news is my boss just bought us all ice cream. This should stop my brain from melting for at least the next ten minutes or so.