[UPDATE: For real-world horror stories of IT vs Web 2.0, see this excellent ComputerWorld article]

On my desk at work I have two ethernet cables. One is black and one is white. The black one is connected to our corporate network. I use that one when I want to print things. I could also use it for Internet access and stuff, but I don't because the corporate network blocks a number of ports, including those used for Skype and Second Life. It's also pretty slow.

The white cable, meanwhile, is a standard consumer-grade DSL connection to the Internet, with nothing blocked at all. Our local IT staff installed it by popular demand, possibly without checking with headquarters (we love our local IT staff!). It's fast. I use it all the time.

These two cables are a handy metaphor for the two worlds of corporate computing: end users and the IT department. The chasm between them has never been greater, in part because the tools available on the wide open web have never been better.

Earlier this year, I described this divide in a controversial post entitled "Who needs a CIO?" Today I returned to the subject, perhaps unwisely, in a speech to, er, CIOs at an Accenture meeting in Boston. I told the story of my two cables not to dis our own central IT department, who are only doing their job of supporting mission-critical applications (Hi guys! please don't block any more ports), but to illustrate that there are really two IT functions in any company these days, and each demands a different approach.

The first is the traditional one of core software functions, from HR to Accounting and file storage and backup. The second is cool web stuff, from blogs to wikis, social networking and, yes, even Second Life, despite my skepticism about its business utility.

I don't think one network approach can suit both. Our PeopleSoft system is crucial to the company's accounting and has transformed our business processes, and I wouldn't want to do anything to put it at risk. Likewise, we need rock-solid data backups, which have saved our skin more than once. So too for other enterprise apps, from our Exchange server to our workflow management. Keeping that stuff running and secure is no joke, and I'd hate to think that it was one of my malformed Twitters that brought it down.

But at the same time we all live online and the distinction between work and life is blurring more every day. Experimenting with the latest Web 2.0 goodies is not only part of being part of the modern age, it's part of our job (we are Wired, after all). I'd hate to think that our PeopleSoft protectionism was stopping us from that.

Hence the need for the second network, which I think of as our sandbox. We can try things out there without fear of endangering our core business functions. 

I spoke to a number of CIOs at the Accenture meeting who were rolling out a similar dual network strategy. Some of them have two physical networks; others create several virtual networks on a single physical one. But all of them understood the need for a sandbox where users could experiment with new software, web services and modes of working without introducing too much risk to the core business.

The technology world inside companies shouldn't be users vs IT, innovation vs. operations. But the main reason that it so often is, that they're so often in direct conflict, is the dependence on shared infrastructure for everything.

Hence my two cables--in a sense, my computing ego and id. Scratch most companies and their employees and you'll find the same. So why not build IT infrastructure that reflects the reality that one size doesn't fit all? To encourage experimentation at the edge while protecting operations in the core, two networks work better than one.