Participants can use such sentences as:
"Mind the Light!"
"Friend, I'm afraid I must elder three for what thee said on First Day."
"Today is the 24th day of Tenth Month, 2007."
"Walk cheerfully all over the Earth."
"George, thy foreign policy is not in keeping with the Peace Testimony."
If you are thinking that most modern-day Quakers don't talk like that, just keep in mind that most modern-day pirates don't talk the way a celebrant of International Talk Like a Pirate Day would. Indeed, most pirates today sail the waters near Indonesia (and may not even speak English) or create bootleg software and illegal copies of movies (and therefore use techno jargon).
Please spread the word! If someone feels Led to create a website for the day, so much the better.