Actually, one guy just showed me one of those smart watches (not apples, just some generic smart watch), and I warmed to them a little bit. Before I would have thought who cares, but when he introduced me that, I actually saw the point and started almost wanting one for myself. And the thing is, He never showed me how it shows the time. As far as i know, maybe it doesnt even show time. Traditional watch option of showing time was not the point for smart watches despite their name, but what excited the guy who showed me that, as well as me, was the other stuff in that smart watch.
This friend of mine had just got bit owerweighed and had started running. What this smart watch did, first of all, it did those simple things, like telling how many steps you took etc. that you can use other devices as well, but then it got bit better. It had GPS, so it was able to measure your speed, location etc. stuff (nothing here that cellphone couldnt yet), but then we got to the things that started to impress me in sense that hadnt came to my mind that could be so useful.
One of the things is, if you start running, it is very easy, especially at beginning to get this painful aching on your stomach, because you are running too hard. Well, this watch keeps checking your pulse among other things, and it warns you before that aching comes, this way you can run hard, without getting that stomach pain from overdoing it, since that watch warns you.
In addition, it also keeps checking your rhythm otherwise too, that if watch notices you are doing too easy, maybe resting for bit too long or something, based upon your pulse and stuff, it will tell you to speed up again, bit like a coach.
It also keeps telling if you are improving. That while you are running, and watch notices you just ran first kilometre much faster than before, it will congratulate you and tell you just broke your own record, and if you did it very slow, it will start to tell you to hurry up and run faster.
It also recognises the hands movement, being able to figure out what exactly you are doing. And it wasnt too easy to fool it. just putting hand up and down didnt make it think you were running, and similarly if you drive a car and car keeps bumping a bit, it doesnt think you are running.
When i saw this all and realised that is just a beginning. I wouldnt be amazed if those things would actually become quite popular at some point. Didnt feel like we were that far away from tricorders anymore.
edit: almost forgot to mention one great thing too. This friend of mine actually owns a computer store, and hence he keeps sitting in front of computers a lot. Well, one of the things this smart watch of his does is to tell him he have been sitting too long in front of his computer and he should get up for a moment.