My vision of Always-On has always been based on the idea that applications would live on the wireless network in your home. A Wi-Fi set-up has both the bandwidth and computing power needed to handle several such applications.

But early medical applications move with you. And thus they ride on the mobile network.

The Mobile-Technology Weblog (the picture is taken from that blog) has an example today from Korea. (It's a small world. The author lives in Munich, he's represented for ads by a British firm, and here I am blogging about it from Atlanta, Georgia.)

The hook is "here's the fat police," but the story is that there's a Samsung SPH-E3330 mobile that can measure your body fat level.

LG seems even further ahead in this area. Its LG-KP8400 can measure blood-sugar levels, diet, and compliance with your prescriptions, even handle long-distance medical consultations. Separately, LG plans to release a "stress phone" that monitors your heart rate next year.

These are all Always-On medical applications, based on the phone and riding the mobile network. They can travel with you, and in a dual-mode Wi-Fi and mobile phone their signals could go out from your home or office.

These are the trends I'm talking about, people. And remember, medicine is just one application space for Always-On, even though it is literally a "killer app."