The devices that contribute to the Internet of Things span personal, household, public, business and industrial spaces, and any area that's not affected by them now likely will be in the future. The smart gadgets that many of us see and interact with daily are our Internet-connected smartphones, which have sensors including accelerometers, gyroscopes, GPS and sometimes heart-rate monitors, but those are just the tip of the iceberg.
In the personal-item sphere, we have wearable devices like fitness trackers and heart monitors that use our phones to send and receive data. Smartwatches, like Apple Watch and Pebble, perform those tasks and many more in conjunction with our phones. Sensors and microprocessors on clothing aren't far behind (and are possible to create now with sewable boards and sensors from Arduino and other companies). Even pets can be added to the list of "things" we can add sensors to for tracking purposes. We also already have cameras that send pictures to the Internet, scales that can share our weight on social media, toothbrushes that monitor our brushing habits and gaming systems that listen for verbal commands.
A lot of household appliances, including thermostats, water heaters, security cameras and lights, can gather data, be accessed remotely and communicate via the Internet when there's a problem. Some even learn your patterns over time to change their settings or alert you when something suspicious happens. Connected garage doors and digital door locks can let you into your home with data from your phone instead of a traditional key. WiFi-enabled stoves and ovens can be monitored or turned off or on remotely. One theoretical appliance that people bring up a lot is a refrigerator that can track its contents and let you know what you're out of or what you could make for dinner with your current ingredients. Be assured, someone is working on it.
We're in the early stages of smart cities, where entire metros are being covered in sensors and other tech. Devices that can take sensor readings and transmit them are ideal for things like utility usage monitoring; in most areas this still requires workers taking meter readings from individual houses. Smart devices could enable monitoring for hazardous road conditions, pollution levels, and water and energy consumption. Roads will (and in some cases do) have sensors to detect potential headaches like traffic and road conditions. Smart cars or smartphones in the vicinity can be alerted to traffic delays. Other potential uses include adjusting traffic lights to suit real-time conditions, monitoring garbage cans to know when they need pickup and providing information on available parking. Scientists are working on tiny sensors to place in cement and other materials so the physical condition of the infrastructure itself can be detected before structural issues lead to disasters such as bridge collapses.
Cars are getting smarter, too. GPS in cars has been a thing for years, and we've had attachable toll tags that pay automatically as we pass through toll stations, but we're starting to add more sensors and computing functions to automobiles. Smartcars can act as entertainment and information hubs, provide WiFi to other devices and track driving metrics (including speed and fuel efficiency). And one day soon, we'll likely have self-driving cars that allow hands- and eyes-free driving, all the while monitoring the road and nearby vehicles to prevent accidents. Already there are cars and services that allow you to start or locate your car and unlock doors remotely, as well as contact emergency services and roadside assistance.
There are already a lot of connected devices in use in the healthcare industry, and many more are in the works. Doctors and other caregivers will be able to monitor patients' vital signs, activity and other important metrics remotely, saving lives and perhaps allowing elderly people to live independently longer. Embedded sensors in hospital beds and garments can also gather important data about patients, and researchers are working on things like carpets that can detect falls and tiny computing equipment that can be injected into the human body.
There are even more smart devices in manufacturing and other businesses where unmanned monitoring can save a lot of time and money. GE experimented with various sensors in the ceramic mixing process for battery manufacturing. The researchers analyzed the data to determine what they needed to monitor to know when the ceramic mix was just right, which has allowed them to get predictably even consistency and greatly reduced defect rates [source: Wasik]. The status and condition of products can be monitored from initial materials all the way to the end of production. Similar monitoring can apply to just about any business. In retail, inventory can be tracked and alerts can be sent when items need restocking. In agriculture, soil and crops can be monitored for irrigation and other needs, and livestock can be tagged and located. In office buildings, environmental controls can be automated to reduce energy waste and cut costs. The possibilities are endless.