There are currently about 3.2 billion mobile subscribers in the world, and that number is expected to grow by at least a billion in the next few years. Today, mobile phones are more prevalent than cars (about 800 million registered vehicles in the world) and credit cards (only 1.4 billion of those). While it took 100 years for landline phones to spread to more than 80% of the countries in the world, their wireless descendants did it in 16. And fewer teens are wearing watches now because they use their phones to tell time instead (somewhere Chester Gould is wondering how he got it backwards). So it's safe to say that the mobile phone may be the most prolific consumer product ever invented.
However, have you ever considered just exactly how powerful these ubiquitous devices are? The phone that you have in your pocket, pack, or handbag is probably ten times more powerful than the PC you had on your desk only 8 or 9 years ago (assuming you even had a PC; most mobile users never have). It has a range of sensors that would do a martian lander proud: a clock, power sensor (how low is that battery?), thermometer (because batteries charge poorly at low temperatures), and light meter (to determine screen backlighting) on the more basic phones; a location sensor, accelerometer (detects vector and velocity of motion), and maybe even a compass on more advanced ones. And most importantly, it is by its very nature always connected.
Project out these trends another ten years. You will be carrying with you, 24x7 (a recent study of Chinese mobile customers showed that the majority of them sleep within a meter of their phones), a very powerful, always connected, sensor-rich device. And the cool thing is, so will everyone else. So what are you going to do with it that you aren't doing now? Here are some possibilities:
Smart alerts: Your phone will be smart about your situation and alert you when something needs your attention. This is already happening today -- eBay can text you when you've been outbid, and alert services (such as Google News) can deliver news, sports, or stock updates to you. In the future these applications will get smarter, patiently monitoring your personalized preferences (which will be stored in the network cloud) and delivering only the information you desire. One very useful scenario: your phone knows that you are heading downtown for dinner, and alerts you of transit conditions or the best places to park.
Augmented reality: Your phone uses its arsenal of sensors to understand your situation and provide you information that might be useful. For example, do you really want to know how much is that doggy in the window? Your phone, with its GPS and compass, knows what you are looking at, so it can tell you before you even ask. Plus, what breed it is and the best way to train him.
Crowd sourcing goes mainstream: Your phone is your omnipresent microphone to the world, a way to publish pictures, emails, texts, Twitters, and blog entries. When everyone else is doing the same, you have a world where people from every corner of the planet are covering their experiences in real-time. That massive amount of content gets archived, sorted, and re-deployed to other people in new and interesting ways. Ask the web for the most interesting sites in your vicinity, and your phone shows you reviews and pictures that people have uploaded of nearby attractions. Like what you see? It will send you directions on how to get there.
Sensors everywhere: Your phone knows a lot about the world around you. If you take that intelligence and combine it in the cloud with that of every other phone, we have an incredible snapshot of what is going on in the world right now. Weather updates can be based on not hundreds of sensors, but hundreds of millions. Traffic reports can be based not on helicopters and road sensors, but on the density, speed, and direction of the phones (and people) stuck in the traffic jams.
Tool for development: Your phone may be more than just a convenience, it may be your livelihood. Already, this is true for people in many parts of the world: in southern India, fishermen use text messaging to find the best markets for their daily catch, in South Africa, sugar farmers can receive text messages advising them on how much to irrigate their crops, and throughout sub-Saharan Africa entrepreneurs with mobile phones become phone operators, bringing communications to their villages. These innovations will only increase in the future, as mobile phones become the linchpin for greater economic development.
The future-proof device: Your phone will open up, as the Internet already has, so it will be easy for developers to create or improve applications and content. The ones that you care about get automatically installed on your phone. Let's say you have a piece of software on your phone to improve power management (and therefore battery life). Let's say a developer makes an improvement to the software. The update gets automatically installed on your phone, without you lifting a finger. Your phone actually gets better over time.
Now, if we can just train it to do your laundry ...