iPad is three years old now, and many tech blogs are writing stories to reflect what has changed. More than 100 million of them have been sold, alongside other popular tablets like the Kindle Fire and Nexus 7. But originally the reception was quite sceptical.

Many made the argument that the tablet was “just a big iPod Touch or iPhone”:

at the end of the day, the show’s centerpiece - the iPad – is just a big iPod Touch. Lots of folks will want it, in a hypothetical sort of way. But it’s hard to imagine all that many of them will fork over the initial $499 for a crippled version

The funny thing about this argument is that — while the skepticism was misplaced — the core point was true: The iPad is just a big iPhone.

Or to put it the other way, the iPhone is just a pocket-sized iPad.

Tablets of different sizes

There was a recent Time interview of the computer science legend Alan Kay. I shared it on Google+, and there was some discussion. I made the following argument:

In the end there are no phones any longer. Just tablets of different sizes, from tabletop (iPad, Surface) to pocketable (what we call smartphones)

The chances are that if you’re reading this post, you will have what you consider a smartphone. Look at it, and consider how you use it. Is it really a phone, or is the way you use it a lot closer to what you’d consider a tablet?

Back in mid-to-late 2000s, we had Nokia’s Internet Tablet devices. We considered them tablets, and did tablet-like things on them. The Nokia 770 tablet had a 4.13” screen. The iPhone has a 4” screen, and the Nexus 4 has a 4.7” screen. And yet somehow the first device was seen as a tablet, and the two latter as smartphones.

The software running on smartphones and tablets is nearly identical, as are the use cases.

Phablets meet in the middle

Smartphones and tablets are converging, quickly. Manufacturers know this, and the device-buying public is starting to see it too. But still the gadget blogs love to diss the large “phablet” devices, even though they sell quite well.

The problem here is that many technology bloggers still try to keep the two categories of devices — smartphones and tablets — separate, even though they really aren’t. Maybe these devices are two big for holding against your head for a phone call, but who really does that anymore?

In reality all of them are tablets — windows on the web — and the only difference is that some of them fit in your pocket, and others need a bag, providing a bigger canvas to see information and work on in exchange.

This is the use case I have. For most of my internet and communication needs, I’m using a Nexus 4 as a pocketable tablet. I also have a larger tablet, which I use as my workstation and for some things where a bigger screen is nicer, like graphic novels.

Some are even able to do all their work on the smaller phablets.

End of telephony

The big news here is that the telephony part of a smartphone is not going to matter for much longer. Internet-based communication tools like instant messengers, email, and hangouts provide richer ways to interact, and don’t tie you down to a specific device, or a specific telecommunications provider.

In the long run, this means an end to phone subscriptions. As I wrote on my “hacker’s toolkit”, buying prepaid data is cheaper and easier:

As the MiFi is only used for Internet access, I can buy cheap pre-paid SIMs from each country I travel to. Paying somewhere around ten euros for a month of Internet abroad certainly beats the usual roaming charges!

This is already happening. For example, Asymco reported on dropping SMS volumes in Spain:

After peaking at the end of 2008 at about €450/quarter, revenues have fallen by 60% to about €171 million in the third quarter of 2012. These figures represent almost 100% operating profit for operators so the impact is felt directly in the bottom line.

The culprit is IP-based messaging. Services like Whatsapp, iMessage and even Facebook offer “free” messaging to users who have a smartphone and a data plan. I’ve been told that 97% of Spanish smartphone users have Whatsapp installed. In some markets this “free” messaging is offered via BlackBerry Messaging.

This obviously is a development telecommunications companies are scared of. But while SMS and call volumes go down, the other change is that all these new devices will have SIM slots, and so the operators can sell a lot more of data plans.

Some of them are already targeting this new world. T-Mobile recently killed their traditional subscriptions and subsidies in favor of prepaid plans.

This is a new world

The computing world is switching to tablets rapidly. These tablets can be smaller or bigger depending on the requirements of the user, but they all are internet-connected, touch-capable and full of sensors. They already fit use cases from software development to watching media or social networking.

This will mean eventual changes in our culture:

My generation will be at something of a loss when this new world comes about. In my life, I’ve been rewarded for communicating effectively online via text. I’m a reasonably effective verbal communicator, but not nearly as good as I’ll need to be to compete with the telepresence-native adults that the children of today will grow up to be.

Today’s digital natives will be tomorrow’s telegraph operators. The only way to survive will be to understand the impact of pervasive video communication before it sweeps us under our keyboards.

PCs will still remain as the main productivity tool for some years, mainly thanks to all the legacy software built around that ecosystem. But the VisiCalc moment of tablets will come, sooner or later:

Every major shift in computing has brought its new big companies. PCs gave us Microsoft, web Google and Facebook. In the tablet space the focus has so far been on hardware and platforms, but I’m quite certain there will be winners in the productivity software space as well, companies that we may not have even heard of yet. Maybe your company is going to be one of them?

For now, I’m considering my adventures in the tablet productivity world an experiment. But day by day, my work tablet setup is feeling more and more comfortable.

Right now I don’t miss my laptop. Or having a phone number.