Before 2007, surfing the web on a mobile phone was a miserable experience. I remember trying it from BlackBerries, Palm Treos, and Windows Mobile devices, and being so frustrated by how slow and unusable it was that I was dying for the day when we’d be able to access the web from a mobile device just as easily as from a computer.

Obviously, that day is here. In fact, it’s reached the point where most of us take it for granted and that’s one of the big reasons why sales of smartphones surpassed PCs in 2011. This trend is accelerating so quickly that a lot of companies are going to be in danger of being disrupted if they don’t adapt and re-think their customer experience for mobile.

Computers are about to get lapped

Let’s take a quick step back.

When the iPhone arrived in June 2007, it was the beginning of sea change that turned smartphones into full-fledged Internet devices. While the first-gen iPhone was severely limited most of the time because it didn’t have 3G mobile broadband, it reinvented the mobile user interface and when you used it on a Wi-Fi connection you could see that the future was having the full power of the web in the palm of her hand.

Before iPhone — and eventually Android and Windows Phone 7 — arrived, 90 percent of the systems that connected to the web were Windows PCs. It’s hard to believe that was only five years ago.

In 2012, Gartner projects that worldwide PC sales will reach about 400 million units in 2012, while smartphones will surpass 600 million units. Tablets will sell about 100 million units. That means that only about 35% of the new devices sold this year that will be connecting to the web will be Windows PCs. That’s how much the technology world has been turned on its head in just five years.

Now, remember that those Gartner numbers are only for new devices sold in 2012. So the overall percentage of Windows PCs accessing the web will still be over 50% in 2012, since there are obviously a lot of older machines still in use.

However, the numbers are going to get more dramatic in the years ahead. PCs are about to get dwarfed. By 2015, Gartner projects PC sales will grow to over 500 million, but tablets will triple to about 300 million and smartphones will leap past 1.1 billion.

Despite the fact that this massive sea change is about to come roaring in, the web continues to be a computer-centric place. While many types of workers and business professionals will use computers to design, build, and create content for the Internet for years to come, the primary access devices that the majority of users are going use to access the Internet will be smartphones and tablets.

The mobile re-think

While iOS, Android, and Windows Phone devices now offer a seriously-capable mobile Internet experience, the mobile web itself still hasn’t take off its training wheels. In most cases, too many websites are still badly prepared to handle mobile visitors because of the way the sites use Flash, mouse-over animations, and other Javascript functionality that is designed solely for a user with a mouse. Unfortunately, when many of these sites offer a mobile version tailored for smaller screens that use multitouch, the mobile site usually doesn’t include all of the functionality of the full site.

That’s why user satisfaction with mobile sites is lower than the overall web, and it’s why users have gravitated toward downloading native apps that are optimized for the mobile experience. The problem with that is it creates a bifurcated experience for companies because they end up developing a separate set of functionality for the web versus native apps for mobile devices. And since every mobile operating system has a different set of development tools, that means a company has to develop a different app for every platform, and try to keep them all unified and updated. That’s impractical and unsustainable — and we haven’t talked about the fact that companies now have to design separate apps for tablets.

This situation is not going to make sense much longer, because within a few years more people are going to be accessing the web from mobile touchscreen devices than from computers. The mobile web will simply become the web. That means every company that builds a website will need to rethink site design so that it’s always friendly for both a big screen with a mouse and a touchscreen device. But, that’s just the first part of the equation. Companies also need to reconsider their entire site experience for mobile, and think about what it could mean for customer service, mobile commerce, geolocational targeting, targeted deals and coupons, and much more.

The bottom line is that this isn’t happening fast enough, and that’s going to create a lot of opportunities for disrupters who can create better mobile experiences and use it to leapfrog incumbents. If you’re not thinking about this now and planning for it, then you could be putting your business at risk. If your competitors have a smoother and more comprehensive mobile experience then it could give them an important edge with customers, especially since users have even less patience for slow site performance and a bad user experience when it comes to mobile.

Of course, this goes for TechRepublic too, but it’s not just for Internet businesses. Every company or organization that has a website and a competitor needs to get serious about this because it’s going to be a sea change on the same scale as the iPhone first bringing the capabilities of full web browsing to the phone — only this change isn’t just going to disrupt smartphone makers, it’s going to affect every kind of company imaginable.