You see them everywhere: Annoying people with Bluetooth earpieces permanently mounted on their ears, whether they're talking on the phone or not.

Those earpieces replicate some of the phone's functionality - namely speaker and microphone, plus electronics for muting, connecting wirelessly and other functions. Nearby, a pocket-size mobile phone houses the rest of the electronics, plus hardware and software for surfing the internet, playing music and videos, taking pictures and other functions.

Meanwhile, the biggest challenges for handset makers revolve around conflicting priorities: How do you make the phone as small as possible, but the screen as large as possible? How do you pack a full-size keyboard onto a tiny mobile phone?

The solution to these conundrums is to move or replicate all mobile phone electronics to the earpiece.

The reason mobile phones are the Mother of All Convergence Devices is that the phone part is absolutely indispensable. People must be able to make or receive calls while jogging, working, lying on the beach - everywhere. The only way to make, say, a camera accessible at all times is to build it into the mobile phone, and the same is true for media playing, GPS functionality and other features. The phone must go with you everywhere, and the rest of the functions are just along for the ride.

Imagine being able to leave your full-featured, pocket-size mobile phone behind if you choose, and carry only the earpiece from which you could at minimum make and receive phone calls.

The benefit is that pocket phones could be bigger - bigger screens, better cameras and more electronics - without compromising mobility when you really need it.

Three recent trends make this possible and desirable: Shrinking mobile phone electronics, advances in voice recognition and embedded electronics everywhere.

1. Shrinking mobile phone electronics

The first time I saw a mobile phone in the 1980s, it (combined with the battery) was the size of a brick - and about as heavy, too. Since then, mobiles have largely obeyed Moore's Law, becoming smaller and cheaper and acquiring ever more features all the while.

Obscure handset makers have already designed, built, manufactured and sold complete mobile phones small enough to fit in an ear-wearable size. Trouble is, they're configured like bigger, traditional mobile phones, not earpieces.

For example, there’s a Chinese mobile phone called the Xun Chi 138 that's 2.64in long and weighs 2 ounces. Despite its size, the phone has a touchscreen for text input.

Haier America launched last year its Elegance mobile phone, which is about the size of two fingers - 3.5in long.

Also last year, KTF Korea unveiled its mini EV-K130 mobile phone, which is about the same size as the Elegance.

Australia's SMS Technology has managed to squeeze an entire mobile phone onto a fairly standard-size wristwatch called the M500.

We have the technology to squeeze a mobile phone into an earpiece.