CON TEXT: Is that it, asks K evin Courtney

Yes. That is all.

But we haven't even started yet.

Then let's begin. Three little words have begun popping up at the end of people's e-mails and blog posts, and it's not "I love you".

So this is some trendy new way of signing off your electronic missives?

The art of letter-writing has changed irrevocably since the advent of e-mail. In the days of Jane Austen, people communicated by creating an interface between a cylindrical ink-delivery device (a "pen") and a flat, ultra-thin sheet of pulped wood ("paper"). It was a slow, painstaking process, each word having to be drawn out by hand, and the ink needing to be replenished more often than a deskjet printer. When the letter was finally completed, the relieved writer would sign off their correspondence with some flowery valediction or other, such as "yours sincerely", "yours faithfully" or "yours in fevered anticipation of a bodice-ripping embrace behind the primroses".

Ah, those were the days. Licking the envelopes, buying the stamps, running down to the postbox, then waiting by the window for days until the postman arrived with a reply. Now it's shoot off a quick e-mail, and the response is pinged back within seconds. Where's the romance in that?

Not only have old-fashioned billets-doux gone out of vogue, but so have all the other conventions of letter-writing. "Dear Hermione" has been replaced by "Hi Herm!", while "Yours eternally" has been ousted by "CU L8R". And 4get speling and pnctuatn. But now, a new convention in e-mail and blogging has begun to assert itself, and it won't be long before every e-mailer and blogger is required by law to end their message with the three magic words: "That is all."

And why is that?

Despite the freehand nature of electronic communication, people still crave some sort of order in their e-mails and blog posts. Bored with the usual inanities, people are looking for a universal sign-off that carries weight and gravitas yet is reassuringly lighthearted. Or, as Julia Lipman of Flak magazine (www.flakmag.com) puts it, "there's got to be an all-purpose way to end a piece of correspondence that makes you sound both careless and reasoned, voluble and down to earth". According to Lipman, "that is all" fits the bill perfectly, "a three-word phrase that literally means the transmission is done and yet connotes so much more".

So who started it?

The man credited with starting "that is all" is one John Hodgman, writer, humourist, journalist, former literary agent and one-time humour editor of the New York Times magazine. As the advice columnist on uber-trendy blog McSweeney's, Hodgman regularly ended his posts with "that is all", and soon the phrase went viral. Look out for it on the next e-mail from your gran.

And why does everyone listen to this Hodgman guy?

A font of all useful (and useless) knowledge, Hodgman has been writing his own popular blog, The Areas of my Expertise, which he has turned into a successful book. On its publication, he was interviewed by Jon Stewart on The Daily Show and subsequently became the show's resident expert on all things under the sun.

Not bad.

That's not all. Hodgman also appears as PC in the iconic ads for Apple Mac computers and is now much in demand to play the brainy nerd with glasses in various TV series, including Battlestar Galactica. But his lasting legacy to the world may well be that soon-to-be universally used valedictory triptych: that is all.

Try at work: "They've put 'that is all' at the end of my payslip - that's really rubbing it in.

Try at home: "Er, don't you think 'here endeth the e-mail' is a bit preachy?"