Oh, dear -- Tasker is a dangerously tempting toy
I've previously mentioned Tasker, the app that lets you do roughly anything with your Android phone. I just happened to be skimming the wiki's list of profiles that people have contributed, and came across this one, which rings US Navy Ship's Bells every half hour.
Which means that, if that's possible, I could program my phone to ring Westminster Chimes.
Intellectually, I'm certain that this would become incredibly annoying *really* fast. But it's still tempting to go looking for the necessary sound files...