No, I don't normally make them either - but having just read a thread about what annoys you - and many people saying 'people talking really loudly on their mobile phones' I am making one.
When sitting next to someone having a loud phone conversation, I'm going to join in!
Suggested scenario:
Him (they are invariably men) Hi, I'm on the train
Me (loudly) It's the Kings Cross to Stevenage if you're interested.
Him: Did you get the quote I sent?
Me: (Loudly) I added an extra 30% because I don't really want the job because it would involve me working on a Friday afternoon and stuff that, that's pub time.
You get the gist?
Anyone else up for it? Ideas for witty comebacks so we're all prepared?