The invention of the junk telephone call is not being greeted with the proper amount of enthusiasm for a technological breakthrough. Because the computerized telephone sales pitch will be able to reach any number, unlisted or not, from any region of the country, at any hour of the day or night, there are those who fear being disturbed when they are in their own homes, eating junk food or watching junk on television.

But they fail to see the possibilities in this method for the ordinary citizen who wants to communicate with his fellow creatures.

At the moment, the chief means of communication in this country are 1) buttons 2) T-shirts and 3) bumper stickers. True, an occasional old-fashioned type who has something intensely personal to say to someone especially dear to him may buy a printed greeting card. But the accepted areas of communication are the bumper and the chest, with the back sometimes used for afterthoughts.

The advantage of limiting human thought to a finite number of printed sayings is apparent to anyone who has listened to people talking off the tops of their heads on CB radio or call-in shows. But there are disadvantages to the button, shirt and sticker, too. It generally means you must select your one message for the day and stick with it until you get back to your bureau drawer or garage. It is limiting to people with narrow chests or bicycles. And it is frustrating to have something to express, but to have to wait for it to come up from the wash.

Junk telephone calls do not carry these limitations. Instead of walking around with a T-shirt indicating that you are sociable, you could telephone the message rapidly to every exchange in, say, a university town. If you just want to say "Have a good day" to all, why not telephone the thought out to strangers 24 hours a day?

The system would have special appeal to children. Those who were brought up in an era when they watch games on television instead of straining themselves by playing them, might want to record their prank calls. The computer could go through the city directory with "Do you have Prince Albert in a can?" while the child got to bed on time.

Of course there are times when you have something to say to only one person. But you might want to say if often. Think what a machine programmed to call home every few days and say "Just wanted to know how you are, folks" could mean to your relatives far away.

How about a message for a straying lover? All you have to do is set the machine, to call that number every few minutes for a month or two, to say, "How come you never call me?"