You probably don’t know his name, but Jack Dorsey came up with what might be the most important invention of the 21st century — Twitter. It must be important because the Library of Congress is going to house every “tweet” that’s ever been twittered. So here’s a memo to those who work at the library: Move that copy of the Declaration of Independence out of the way, put that first edition of de Tocqueville’s “Democracy in America” somewhere in the back, and find some other place for the contents of Abraham Lincoln’s pockets on the night of his assassination. Make room for messages like, “I should really wash my hair.”

In case you don’t know, Twitter is an online “social network” in which people say just about anything they want as long as it’s 140 characters or less. You can reach millions of people instantly. It’s as if you were shouting out your window — really loudly. Every message is called a “tweet.” Some 55 million tweets are posted every day. That makes billions of them so far. Approximately 75,000 tweets have been sent since you started reading this column. I guess they’re going to have to install a few new shelves in the library to make room for all those tweets.

The Twitter folks suggest that those using Twitter answer the question, “What are you doing?” So the vast majority of tweets are similar to the ego-thoughts that appear on Facebook and MySpace. You find things like, “I’m going to go for a walk on the Third Street Promenade.”

“Changed my mind. Not going for a walk.”

“My head itches.”

These are the kind of statements that will be shelved next to rare copies of the Bible, notes from the House Un-American Activities Committee, and that 130-year-old edition of Whitman’s “Leaves of Grass.”

Maybe I’m not being fair. In addition to daily drivel, there have been some news scoops on Twitter. That’s one of the interesting things about it. If you happen to see a tsunami coming your way, all you have to do to let the rest of the world know about it is to type something like, “Whoa, big wave coming. Looks like a tsunami. Get to safety, but first warn everyone you know about it.” Of course, I don’t know if sitting and typing while a tsunami is heading your way is the wisest course of action.

Another example of the site being used for an important purpose occurred when President Obama announced that Joe Biden would be his running mate simultaneously using e-mail, text messages, and Twitter. Presumably, the next time the United States decides to go to war, we will announce our intentions on Twitter: “We warned you, you didn’t listen, so here we come.”

On the other hand, just think of all the lives that would have been saved if Twitter had been available in the past. When a warring country was ready to quit, instead of calling for a peace conference and waiting for it to convene while the war raged on, heads of state could have just written, “Surrender. Enough already.”

One drawback of Twitter when it is used for newsworthy events is the 140 character limit. This could cause problems like this: “Have just discovered a cure for the flu virus. I haven’t told anybody else what the secret is. It was really very simple. All I did was syn … .” Then what happens if the person typing that important message has a heart attack before he’s able to finish his thought, start up another tweet, and pass on his secret to anybody else? If he had just told the researcher who sits across from him instead of tweeting … .

If you have the same first reaction that I did, you’re probably thinking that the trivial stuff that’s usually on Twitter has no business in the Library of Congress. However, after thinking about it some more, I feel it’s perfect for the library to tackle the tremendous task of tagging all the tweets that have been twittered every since twitterers started talking in tweets. Yes, most tweets are trivial. However, this kind of personal trivia is precisely what millions of people are involved in every day. So it will certainly give future generations an idea of how people spent their time in the beginning of the 21st century. Don’t you think it’s important for those future earthlings to understand why people in our time cared whether a stranger was just about to shave? I’d certainly like to know.

Lloyd Garver has written for many television shows, ranging from “Sesame Street” to “Family Ties” to “Home Improvement” to “Frasier.” He has also read many books, some of them in hardcover. He can be reached at lloydgarver@gmail.com. Check out his website at lloydgarver.com and his podcasts on iTunes.