When that Shakespearean windbag Polonius said "brevity is the soul of wit," he didn't know that 400 years later there would be something called Twitter to try to prove him wrong.

What? You haven't heard about Twitter? Where have you been? Everybody you know is on Twitter, don't you realize? And if you don't get on Twitter RIGHT THIS MINUTE, you are a hopelessly out-of-touch square.

(Do kids still say square? No, kids these days -- and I instantly betray my fogeyhood by using the phrase "kids these days'' -- probably have appropriated some random word, like "waffle" or "Canada," to replace "square" and "uncool." Because that's what kids do, just to mess with their parents' heads.)

For those not up on the latest Internet "revolution," Twitter is in the middle ground between blogging and a social-networking site (like Facebook or MySpace). On Twitter.com, one can start an instant blog, where all the posts -- called "tweets" because federal law requires everything on the Internet to be too cute for words -- can be no longer than 140 characters, the length of a text message on your average cellphone.

What can you say in 140 characters? That's the interesting challenge to Twitter -- because what you write can be as profound or as mundane as space permits. Besides, you can send as many tweets as you like, so you can tell the world every passing thought.

Of course some passing thoughts aren't necessarily worth passing on to others. On Sunday, someone I "follow" on Twitter (i.e., someone whose posts my account is set up to list automatically) opined, " 'Celebrity Apprentice.' Who the hell cares?" -- only to add, about 20 minutes later, an adios to contestant Dennis Rodman.

At other times, getting quick updates from an event is a thrill, a chance to live vicariously through another person. On Saturday night, I enjoyed updates by The Los Angeles Times ' pop-music critic (with whom I worked at my college paper) from a Prince concert at an L.A. nightclub.

Sometimes the entries can be bizarrely poetic. One of my coworkers posted this "Twitter haiku" to explain her Sunday attitude: "Tired, headachy; Thin mint and Bugles diet; Related? Maybe."

And for all the hype and the backlash ("The Daily Show" and "Doonesbury" both slammed the media's Twitter obsession this month), Twitter's immediacy and global reach cannot be denied. Some of the earliest information on the Mumbai terrorist attacks, and accounts from inside the airliner that crash-landed in the Hudson River in January, came through tweets from eyewitnesses.

One of the Tribune 's editors, who has championed Twitter's applications to journalism, says it's a good place to cultivate sources and leads, plus it's a way for journalists to show their human side.

But what's great about Twitter from a human standpoint -- that it's an equal playing field, where schlub and celebrity share the same 140-character limitations -- is troubling on a journalistic level. When a trained reporter's posts run side-by-side with the ramblings of Joe Blow from Kokomo, what happens to credibility? Or has the Internet once again rewritten the rules of journalism, leaving us waffles again scrambling to make sense of it?

Sean P. Means writes the Culture Vulture in daily blog form at http://blogs.sltrib.com/vulture. You can follow Sean on Twitter at @moviecricket