A year ago in this space, I pronounced the dawn of a new era of computing. With mobile phones selling in the tens of millions, PDAs saturating the market and laptops consistently outselling desktop PCs, I said we'd entered the age of device computing. I was wrong.Quite frankly, while mobile devices are amazing in their capability and power, they deliver very little value if they aren't connected to some other computer or service. For the most part, these devices are little more than beautifully designed, computationally rich I\/O and storage devices. It's not until you add a connection - a radio, Internet relay, cable or docking station - that mobile devices become truly useful and exciting. So to say that we'd entered the age of device computing was to miss the point.Certainly, we are moving to a new paradigm in computing, and it's easy to see how mobile devices might get all the attention. The device is the end node of a connected system of computing that fundamentally changes the way applications and data are delivered to the point of interaction. I call this system service-based computing.Service-based computing delivers applications and data from a managed computing platform to a relatively simple end device. In doing so, it puts the onus of managing the computing environment on the service provider and liberates the end user to engage with the information. Service-based computing is the future model for nearly all computing and communications.The market has been building to this model since 1997 with the first ASP application. At DEMOmobile earlier this month, we saw plenty of evidence that service-based computing is upon us. Companies such as Pepper Computing and Route 1, as examples, take different approaches, but the result is the same: The user gets a complete computing experience without having to endure the hiccups of hardware and stutters of software. These are systems that simply work, and work simply.The saturation of mobile devices in today's market has changed user expectations, and perhaps this as much as any advancement in the state-of-the-art of technology is driving us inexorably toward the service-based computing model. Even the most tech-savvy folks don't have the time, inclination or patience to wrestle with configurations, endure service gaps or put up with long learning curves.As service-based computing takes hold, it must fulfill a promise of a simpler, more reliable, even more enjoyable end-user experience. This puts tremendous pressure on the technology industry to deliver fast and stable operating environments, focus development resources on usability, and build coverage and reliability into wired and wireless networks. It also liberates users to focus on information rather than information technology.Shipley is executive producer of The Demo Conferences, a Network World-owned event that showcases emerging technology products and services, and a veteran technology watcher. She can be reached at email@example.com.