What do Apple (AAPL 0.50%), Corning (GLW 0.65%), and Google (GOOG 0.81%) (GOOGL 0.72%) have in common? Whether you noticed or not, they have all become absolutely indispensable to millions and millions of Americans today.

When we asked three Motley Fool contributors with serious technology know-how about the companies they couldn't live without nowadays, those were the names that rolled off their tongues. Everyone uses Google every day, right? And would life be worth living without an iPhone at your side? And if you pull back the curtain, Corning is one of the wizards really making things happen behind the scenes.

Alright, you want to know more. Just keep reading right here:

Daniel Kline (Apple): Apple has wormed its way into people's lives to such an extent that some of its customers would be willing to give up just about anything rather than forgo their iPhones. A survey of 1,200 college students showed that those surveyed ranked their iPhones at the top of a list of 77 options for "what's in on campus."

That puts the smartphone ahead of both drinking beer -- which came in seventh -- and hooking up -- which was way down at 12. This survey was less than scientific and it did not pose the question, "would you give up sex or beer for your iPhone?" -- but it was indicative of just how ubiquitous the iPhone has become.

This result simply confirms an earlier survey in England's Daily Mail, which asked 3,583 women over age 30 about their smartphone-after-dark habits. That study found that 48% of women surveyed said that they consider in-bed iPhone access more important than sex with their partners.

That's a bit extreme, but it's not markedly different from my own reliance on Apple's smartphone. While I will put it down when appropriate -- (I'm a happily married man) -- I'm not likely to go 15 minutes during my waking hours without glancing at my phone. From email and text messages to social media and GPS, I simply can't imagine functioning without an iPhone.

That has kept me loyal to Apple, and made me unwilling to try any other phone, even though I rationally know that cheaper options would likely serve me just as well.

The view from Google's offices in Belo Horizonte, Brazil. Source: Google.

Tim Brugger (Google): Sure, we could live without Google -- if we had to. But it's become such an integral part of the lives of billions of Internet users and mobile device owners that the notion of foregoing the use of Google-related sites, search, and operating systems seems ludicrous.

As of last month, two-thirds of the searches conducted on the world's desktop PCs were via Google, and when all devices are factored into the search mix, the disparity is even greater. As of July, more than 89% of all online searches were of the Google variety. Google is Internet search, plain and simple.

A primary reason why Google is in a league of its own is its Android operating system. Like search, Android's piece of the mobile OS pie is staggering. As of Q2, just shy of 83% of all smartphones on the planet were running Android, which not surprisingly comes Google-search ready.

Google's leading search position -- in part thanks to its widespread Android OS adoption -- is what's driven it to become a behemoth, with $430 billion in market capitalization. Google isn't the largest company on the planet, but give it some time.

With billions of Internet users online, and billions more on the way as Google launches its solar-powered drones into orbit to beam connectivity to the under-served masses, its stellar growth should continue.

If there are lingering questions, or perhaps its sheer size and reach weren't enough to convince you that the search king has become indispensable, I'd suggest you "Google It."

Corning Fibrance lighting fibers. Source: Corning.

Anders Bylund (Corning): You know, Corning is quite literally always with you. Every day.

I'm not talking about the CorningWare kitchen tools, which haven't been a part of the glassware and ceramics giant's operations since the year 2000. No, Corning has moved up to focus on more high-tech materials. The company has moved from your kitchen to your pocket.

If you're reading this article on a tablet or smartphone, there's a good chance that the screen is covered in specially hardened Corning Gorilla Glass. Both Apple and Samsung, for example, use Gorilla Glass in their iPhone, iPad, and Galaxy product lines.

Or maybe you're using some newfangled set-top box to read this on your big-screen TV set instead? That's cool -- Corning probably made the glass for that screen, as well. That's Corning's largest division, accounting for 38% of the company's core sales in the recently reported second quarter.

Either way, the bits and bytes making up these very words were most certainly transported over some of Corning's fiber optic cables at some point. Even if you don't have fiber service yourself, that technology forms the backbone of the Internet itself.

Yes, the cell tower you're connected to is likely to have a fiber line drawn to the nearest interconnection hub. This is Corning's second-largest division, but also the fastest-growing segment.

And there's more. You'll also find Corning materials in air and fuel filters, Pyrex-branded lab equipment, advanced optical lenses, and more.

If that's still not enough, the company invests heavily into finding the next great market for ceramics and glass materials. Corning spends 8.3% of its incoming revenue on research and development today. By contrast, Apple only funnels 3.4% of its revenue into further research.

Corning may have moved out of your kitchen, but you would definitely miss this innovator and leader in multiple markets if it went away completely.