Buying a phone involves too many trade-offs. This one has a great camera, but the battery kind of sucks. This one lasts forever, but it's giant and feels like a car tire. Phones with a single, otherworldly feature, like the Lumia 1020 or the Droid Turbo, are just novelties: great when you need a camera or a big battery, but the rest of the time it's just a fat phone.

It doesn't have to be like this—and soon it won't. In the near future, you'll be able to build a smartphone to your exact specifications. Even better, you'll be able to change the configuration after you buy it. Your gadgets won't be fixed things, upgraded annually. They'll come in pieces, which you'll change constantly to suit your every need and whim. Anyone will be able to afford one. It'll happen first to your phone, then everything else.

We're at the dawn of the age of modular gadgets, and it's going to be awesome.

Build-A-Gadget

Rangan Srikhanta, CEO of One Education in Australia, is sold on the future of modular devices. He's working on the XO-Infinity, a modular laptop/tablet hybrid in the legacy of the One Laptop Per Child project. The appeal of the Infinity is obvious: Buy one device, use it forever. You can upgrade individual parts as you need to, but you only need to endure the high cost of an entirely new gadget once. Much of the world can't afford to upgrade even the cheapest phone every couple of years, but modular gadgets can turn upgrades from a major expense to a minor tweak. Maybe your phone will need a new camera eventually, but the rest of it works just fine. Why pay for new versions of parts you already have?

"So often the cost analysis is, 'Hey, what's the up-front cost?'" Srikhanta says. "But very little has been done on the long-term cost, if you apply that over a child's full childhood." It's still early to say for sure, but Srikhanta is confident that "we're going to come in a lot more cost-effective than getting new cheap tablets every few years.

The Infinity is far from the first of its kind. Modular tech projects have been springing up for years. There was the Motorola Atrix, the phone that wanted to also be a laptop but actually didn't do either very well. And the Asus Padfone—see above. Way back when, you could even pop an MP3 player or a camera into the slot on the back of your Handspring Visor.

The XO-Infinity, a modular laptop / tablet hybrid from One Education. One Education

The difference is that these pieced-together devices are finally feasible now. CPUs are more powerful and more integrated, pulling everything from the Wi-Fi chip to the processor and GPU onto a single, tiny board. USB-C is reversible, wildly compatible, and capable enough to handle some intense throughput. And as more capability shifts to browsers and the cloud, you don't need so much hardware anyway.

As they get better, they're breaking into even more pieces: Google's Project Ara, the most high-profile project in the space, dissects a phone into swappable modules for the battery, the processor, the camera, the screen, and so much more. Want an X-ray machine on your phone? Just pop it in.

Right now, the technology is controlling us. It needs to be vice-versa.

It's not only easy upgrades; repairs are easier, too. One Education is looking into sending the devices unassembled, and just by learning how to put it together the first time, kids will teach themselves to repair and upgrade the devices later. It's cheaper for One Education: The company won't have to replace the whole device every time something breaks.

The Infinity comes in five modules: the core frame for the device, the battery, the camera, the screen, and the computing and networking chip. It can run Linux, Android, or Windows, depending on which module you plug in. Everything connects through USB. Srikhanta is especially excited about USB-C, which the Infinity will support soon—at the moment, there's not enough support for the new connector, especially among lower-end components like those in the XO-Infinity. But here's the beauty of modular technology: That won't slow production down. They'll just swap a USB-C module into the default set later.

One Education is looking at other possible modules to build, but Srikhanta says there are no plans to create a gigantic store full of third-party modules. Instead, Srikhanta wants build a sort of gray market, where people are selling and trading their modules. The only way a device like this can work is with a sprawling, vibrant support system, where it's easy to find the replacement or upgrade quickly and at an affordable price. Where everyone can get what they need.

As Srikhanta says over and over again, no two users are alike—so why should their gadgets be?

One For You and You and You... and You

Alireza Tahmasebzadeh is a co-founder of Blocks Wearables, which is in the middle of building a totally modular smart watch. He says the idea for its modular device came from disagreeing with his co-founder about what should go into a regular smart watch. Tahmasebzadeh wanted contactless payment and gesture control; Serge Didenko, his co-founder and an athlete, wanted heart-rate and galvanic skin response. "So we said OK, we can't put everything here," Tahmasebzadeh says. But, in true young-startup fashion, they wanted it all—so they decided to build a watch with a modular band. The band is made up of a series of interchangeable, hot-swappable links that could contain any combination of these sensors. You can even swap the watch itself on the fly, switching from a round one to a square one. Each co-founder got exactly the smart watch he wanted, in the same device.

"Right now, the technology is controlling us," Tahmasebzadeh says. "It needs to be vice-versa." He remembers when smartphone manufacturers used to try weird things—Samsung would stick a pico projector inside a phone, Nokia would make its phone mostly a camera. Now, everyone's just competing to be the thinnest and prettiest.

The Samsung Galaxy S6 has no swappable parts; neither does the Apple Watch or the new MacBook. High-end devices offer little to no customization, so they compete based on look and feel. They shave off tenths of millimeters of thickness just to stay competitive, forgoing camera fidelity, battery life, and anything in the way of unique features. Trust me when I say this: The Samsung Galaxy S7 is not going to have a pico projector inside.

Nexpaq adds a modular case to your smartphone. Nexpaq

The real question now is, do you, dear reader, want this stuff? Tahmasebzadeh is betting you—and a whole new class of early adopters—do.

So is Vlad Ivanovski, who's about to start raising money to make his MODR case, which lets you add battery, camera, and other modules to a case on the back of your Android phone. "Every phone has gaps," he says. "Every mobile device has gaps." MODR's job is to fill them with batteries, memory, pico projectors, and gigantic Bluetooth speakers.

It's not an entirely unproven market. Clearly, consumers are already on board with the idea of customizing our gadgets. We bump up smartphone camera capabilities thanks to products like Moment or Olloclip; or add storage, thanks to Mophie's new Space Pack. Then there are the crazy add-ons, things like air-quality sensors brought to us by the likes of MODR or Nexpaq (a buzzy Kickstarter project that has already tripled its fundraising goal). Use them when you need them, take them off when you don't.

Of course, those who crave thinner, prettier devices won't be appeased. Project Ara, MODR, the XO-Infinity, and every other swappable product you can find are comparatively large, blocky, and unappealing. But Srikhanta doesn't think they will have to complete, at least not everywhere. "In a school environment, you have two calculators you can choose from. And they haven't changed in ten or 15 years. Decades, really." Basically they work because they work. And that's the whole promise of modular tech—it does exactly and only what you need from it.

But it's not truly being made for the average consumer. The most powerful implications for these devices will be seen in developing countries, in places where the competition is not between the latest Galaxy handset and the latest iPhone. The first Ara devices, which will initially launch out of restyled food trucks in Puerto Rico, will cost as little as $50.

Thanks to fast, cheap processors, standardization of USB and HDMI, and the total commoditization of so many sensors and processors, an entirely new group of people is going to be able to buy a phone and trust that it'll change as they do. It'll be a phone they can use for years, far beyond the lifespan of your average Samsung. The perfect device for today can be reborn as the perfect device for tomorrow. These big, blocky, high-tech Lego bricks are going to change everything.