Today’s Straight Dope Column:
What is the Holy Grail? (Orig. pub. April 4, 2003) now comes with an added footnote:
This, and the New York Daily News article linked, are whooshes, right? Something about the linked article doesn’t pass the sniff test. (But, that could be said about a whole lot of N Y Daily News articles, no?)
The NYDK article is dated March 31, not April 1.
Lots of newspaper articles are dated the day before.
I don’t know of any Church historian or Arthurian scholar who has ever said that there was a real Grail cult. (I would almost say “real Grail”, except that, obviously, there must have been some cup used at the Last Supper, whether it was preserved or not.) This story just goes against everything I know on the subject, and requires a great many unrelated facts to be suddenly and simultaneously turned on their heads.
Yes, but rarely when it’s intended as an April Fool’s joke.
I remember a Superman story from the 50s that was titled “The Night of March 31st”.
That’s not the cup of a carpenter!
Just Googled “Athletic cup of the Carpenter” and go zero hits.
Thank ghod.
Well, Karen didn’t need one, but Richard would.
“Choose wisely.”
There’s at least one hit now, thanks to you. 
This quote from the article hints at their claim:
Which is explained better in this article: Jewel-encrusted goblet found gathering dust in tiny Spanish museum 'touched the lips of Jesus and is in fact the HOLY GRAIL' say two historians with evidence to prove it | Daily Mail Online
Were innkeepers in the habit of using onyx dinnerware back then?
"And he took a cup, and gave thanks, then took another look at the cup and said “Verily I say unto you, I knoweth not who arranged this shindig, but I am not paying extra for this.”