NEXT TO OAFS who use cell phones in movie theaters, telemarketers are the most annoying people in the world. But there are ways to minimize their intrusion into your life. One of them is to use the same technology they use to annoy you.

For a year now, a $40 gadget called the TeleZapper has been a hot seller (www.telezapper. com) among the telemarketer-weary. It works by fooling the predictive dialing software that telemarketers use into thinking your phone number has been disconnected.

When it senses a disconnected number, the software ends the call and removes your number from its database. That means the telemarketer's system won't call you again. Since big telemarketing firms typically work for many clients, getting your number out of one database can eliminate repeat calls.

By most accounts, the gadget works well, although it's not perfect. It can't fool telemarketers who don't use sophisticated software, so small-time operators and local charity solicitors who dial by hand won't be affected by it. Still, it's better than nothing.

After we ran a story about this subject last week, several readers sent e-mail informing me that you don't need a TeleZapper to foil the storm door salesmen. All you need is a PC, a regular answering machine and a few minutes of your time.

It turns out that the TeleZapper works by emitting the first of the three Special Information Tones (SITs) that the phone company plays before it announces a disconnected number. You've undoubtedly heard them: "Dah, dah, dee ... The number you have called is not in service."

When predictive dialing software detects the SIT, it assumes your number isn't valid and chucks it out of the database.

You can find recordings of these tones on the Web in an audio file called "sit.wav." It can be downloaded and played by Windows Media Player or virtually any other audio software.

To find the file, go to Google.com and search for "sit.wav"; I found the file and a good explanation of the technology at the Sweetwater Computer Center's Web site (www.compulore.com/ zapper.htm).

To put it to work for you, download the file and save it on your hard drive. If your answering machine isn't near your computer, you'll have to disconnect it and plug it in near your PC for a few minutes.

Hold the answering machine so its microphone (usually a small depression on the top) is near your computer speakers. Start recording a new greeting, then immediately play the tone file and recite your normal message. Add a few words explaining the tones if you think your callers will be confused.

That's all there is to it. When I tried it and monitored several calls that appeared to be from telemarketers, they disconnected immediately after the SIT played, while a couple of others got through to our voice mail. Obviously, it will take weeks or even months to figure out if the countermeasure works in the long run, but I figure there's no harm in trying.

If you want to get fancy, you can call up the sit.wav file in any audio-editing program (including Windows Sound Recorder) and delete the last two tones. This will make the finished sound file less intrusive to legitimate callers. But some anti-telemarketing crusaders believe the villains will eventually try to get around TeleZapper by listening for all three tones, instead of just one. So leaving them in may be a good idea.

One caveat: Unlike TeleZapper, which emits the tone when you answer any call, this system only works if you let your answering machine or voice mail pick up the line.

Many people think it's rude to have their answering machine screen their calls. If you're one of these polite folks and you answer a call with a telemarketer on the other end, you're out of luck. But even if it only works when you're out of the house, it can weed out plenty of professional annoyers.

Tech support winner

If hardware and software companies want to learn how to do technical support right, they can look to Sears for an example. That's Sears, as in the department store.

I discovered this last week when the remote touchpad on our garage door opener stopped working. Normally, this means it needs a new battery. But when I replaced it, the touchpad still didn't work.

My wife (she-who-forgets-nothing) dredged up the manual she put away when we bought the garage door opener 10 years ago. After reading it, we followed the directions for reprogramming, but still had no luck.

So I turned to the Web, which turned up the Sears Garage Door Opener Help Line (no kidding, they have one). When I dialed the toll-free number, I got a real human being who actually knew something about garage door openers.

On the first try.

On a Saturday afternoon.

At his suggestion, I took a cordless phone into the garage, and he talked me through a couple of tests. When we still couldn't get it working, he gave me the bad news: The touchpad was broken and would have to be replaced.

I wasn't upset, because the touchpad had done its job for 10 years exposed to wind, sun, rain and snow. That's a decent life expectancy. So I ran over to Sears, bought a new one, and had it working in 10 minutes.

In an ideal world, the technician would have been able to solve the problem, but at least I didn't have to spend hours trying to figure out what I was doing wrong. That's good enough.

Henny Youngman lives

This has nothing to do with technology, but I had to share the story.

After three days of squeaking around the house with laryngitis last week, my wife asked me to call the doctor on her behalf and make an appointment.

I dialed the doc and got a cheery voice on the line, which engaged me thus:

Voice: Good morning, doctor's office. Can I help you?

Me: I'm calling about my wife. She has laryngitis and hasn't been able to talk for three days.

Voice: And you're complaining?

I swear it happened.