A 4-conductor TRRS style 3.5mm stereo headset jack is also provided, adding microphone and pause/resume/next/previous functions to the stereo earphones.

And if your phone does not have a headset jack, you may also need to buy a small adapter, which runs about $30.

In the meantime, note that even these bare-bones phones offer illuminated keys, speed dialing and a vibrate mode; all but the Jitterbug have text messaging and a headset jack.

The power button is located at the top along with 3.5mm headset jack, and Micro-USB port is present at the bottom of the smartphone.

"I noticed my experiment was annoying my wife, who felt shut out," he reported in his book, so he ordered the addition of a second headset jack and the orange button.

The 590a ($250, plantronics.com) connects by using a small transmitter box that connects to the headset jack on your music player or PC.

The headset jack serves a dual purpose, as it is also used for the accessory camera.

The device sits on top of your ear, again, like a hearing aid, and in the model they were demoing, it's connected via a wire to your cell phone's headset jack.

The machines are compliant with the Americans with Disabilities Act of 1990 through use of braille and a headset jack.

The phone passes the Federal Communications Commission's safety tests and, like all of the phones reviewed here, comes with a belt clip and a headset jack if you're especially worried.