With Microsoft's announcement at PDC this fall and with the continued growth of Amazon's EC2 service and Google's AppEngine service, the industry seems to have people's heads up in the clouds. With this shift of focus, though, comes a myriad of questions about reliability, security, and portability. Potential customers of the cloud want to know that it can indeed be depended on. Executives want to know that the security of data in the cloud will not be compromised. Software engineers want to know that if a certain provider evaporates into thin air, minimal effort will be required to move deployed assets and keep mission critical apps moving.

With so many questions about elastic hosted services, and an as of yet unclear track record for the same, I cannot help but wonder if the cloud computing model will really take hold, or if it will just be a bridge to an even more impressive generation of computing architectures to follow. Maybe it will be both. This discussion then begs the question — of what that generation will look like that does follow.

Nearly 10 years ago, a program was created that would compel sci-fi geeks, amateur astronomers, scientists, programmers, and scholars to change their screensaver. SETI@home launched in 1999 and over the next 9 years would bring grid computing into the living rooms and dorm rooms of over 5 million people. The original software was an app and screen saver that would use idle computer time to drive the search for extraterrestrial intelligence. It harnessed the untapped power of millions of computers with unrealized potential. It was built as an experiment, to break free of the constraints imposed by a supercomputer. Even hosted clusters have their limits, and some problems go beyond those limits.

With cloud computing the sky is the limit, but what if this world is not enough? What if a single company's data centers won't cut it? What if you want to maintain your data center, while still being able to tap additional resources on demand? What if you wanted to maximized and monetize under-utilized computational resources, instead of just writing them off as depreciating assets each year?

That seemed to be the aim of now defunct CPUShare. It offered users the opportunity to sell their idle CPU time to people who needed computational resources. What if the spirit of this project was matched with the vision of Windows Azure, or the ease of entry of Amazon's EC2. What if it added storage into the mix, RAM, and even bandwidth? What if each of these was currency in a new economy? This new economy would not be comprised of just one company's slice of the cloud; it would be the whole thing.

Crowd sourcing CPU hours might very well be the future, or it may be a pipe dream that will never be possible. It has the same questions of reliability, security, and portability, and it brings with it the question of control. The way the industry deals with the questions about cloud computing today, could very well pave the way for crowd computing to be the driving force behind Web 4.0 and beyond.