There's a lot of talk about wearable technology right now. Samsung just launched the Galaxy Gear and Apple are rumoured to be well into the development of an 'iWatch' device. I really like the idea of wearable gadgets as a supplement to other devices, but I think there's an important question that such items need to answer before they become as popular as the now ubiquitous smartphone.
If you take it off will you miss it?
Many of us have become so used to having the functionality of a smartphone available to us at all times that if we were to forget it and leave it at home all day it's absence would adversely affect us. That's not to say we're addicted (necessarily) or that we're reliant. This means that the smartphone has come to handle so many tasks so elegantly that we naturally defer to it in these duties. A smartwatch, as a topical example, needs to do more than display your texts for easy viewing. If all the smartwatch does is replicate the functionality of your phone, then without it you'll just reach into your pocket and carry on with your day. It needs to provide functionality that your phone can't manage alone.
The Nike Fuel Band is a great example of something along these lines, and biometric sensors are amongst the most popular iWatch rumours. This would be a cool direction for a smartwatch to take, and would of course be reliant on developer uptake of the technology to really prove it's usefulness. It still has to provide us with information that we care about and that is useful. For many people a pedometer alone simply isn't enough. In the end it will be a combination of practical capabilities and simple convenience that make wearable gadgets 'essential' to people that adopt them. This combination is lacking from every current contender.