When humans carry connected devices, they become connected themselves - points on the Internet of Everything. The smartphone - a ubiquitous technology in much of the western world - provides a two-way gateway to the virtual world. We draw information from that world and we contribute data - from our location to our restaurant reviews. The more we tell our phones, the better they understand us. Google Now, Google's mobile "personal assistant" cross-references present location and past behaviour, adding information drawn from the user's email account. Apple's Siri and Microsoft's upcoming digital assistant, codenamed Cortana, offer competing services.

Eric Schmidt, Google's executive chairman, described Google's policy as "to get right up to the creepy line, and not cross it". Sometimes, the knowledge a phone can now display about its owner comes close to that line. You might forget a meeting, but your phone won't - and it can check the traffic to get you there on time.

As sensors become smaller and more sophisticated, the ways phones can listen to us multiply: Samsung's new S5 includes a dedicated heart-rate monitor, designed to integrate with its new fitness app.

The mix of health-consciousness, mobility and connectivity enables unconventional and revealing new approaches to personal health. Massive Health - acquired in 2013 by Jawbone - built a simple app called The Eatery. Users photographed their food, uploaded the picture and gave it a score for how healthy they thought it was. Other users then rated the photograph. It rapidly became clear that people believed that they ate more healthily than others, even when eating the same food. A slice of pizza would, on average, seem 2.5 times healthier to the person eating it than the others who judged it.

Fitness has also driven adoption of what promises to be the next wave of devices connecting us to the network: wearable technologies. The first of these to take off were little more than smart pedometers. These have developed into a competitive market of smart, fitness-oriented products, which includes the likes of the Fitbit Flex and Jawbone UP.

Meanwhile, just as demand from customers has made phones evolve, a new generation of versatile wearables is making its presence felt. Google Glass is still the preserve of early adopters, but new, more fashionable frames are being released, continuing a move from geek to chic.

The wristwatch, nearly made extinct by the phone, is making a comeback using smartphone components. Pebble Technology raised $10 million (£6m) on the crowdfunding site Kickstarter to make its e-ink "smartwatch", designed to synch with a phone, but with apps for the watch itself. Samsung and Sony have launched their own connected watches, with Apple's entry into the market a persistent rumour.

Consumer analysts Canalys say that 2014 is the year smart watches and other wearables become a key consumer technology, with sales expected to reach 8 million, growing to 23 million in 2015 and 45 million by 2017.

The smartphone brought many devices - phone, diary, watch, camera - into a single form. As connection becomes simpler and more intuitive, wearable devices may create a network on every body, as specialised, wearables - lapel cameras, audio recorders, heart monitors, watches or lenses - connect to a smartphone or tablet that forms the hub and control centre. Freed from the form factor of a slab with a screen, designers can experiment with new applications and new designs, such as Bionym's Nymi wristband, which uses the wearer's unique heartbeat as a key to unlock other devices, or the electronic tattoo that has been patented by Motorola.