Not to be a party-pooper on π day, but the excellent Tau Manifesto seems to have gotten an update in the time since it was first published, now with rebuttals to common arguments against the π-loyalists.
My favorite new section, towards the end:
But what about puns?
We come now to the final objection. I know, I know, "π in the sky" is so very clever. And yet, τ itself is pregnant with possibilities. τism tells us: it is not τ that is a piece of π, but π that is a piece of τ—-one-half τ, to be exact. The identity eiτ=1 says: "Be 1 with the τ." And though the observation that "A rotation by one turn is 1" may sound like a τ-tology, it is the true nature of the τ. As we contemplate this nature to seek the way of the τ, we must remember that τism is based on reason, not on faith: τists are never πous.
Remember, τ day is June 28.