Every now and again just about every body runs into a situation where they wish they had ready access to an extra shared storage drive so they could easily share a file with somebody else.

Of course, if you have an IT department you can set that up easily enough, but the length of time you need access to the drive might not justify the time it would take for the IT people to set that up. Of course, you may not even have an IT department handy at all.

That's what makes a new cloud computing service from a company called Etelos intriguing. The Etelos Server is essentially a shared virtual network drive that people can access as service. So rather than delivering an application as a service, Etelos is giving customers an ability to essentially deliver data as service. Whether customers opt to build an application on top of those virtual drives or just use it as a shared storage device is up to them.

Etelos, of course, is no stranger to the application-as-a-service arena. The company built what it describes as a marketplace that allows companies to easily buy, sell and distribute applications hosted by Etelos. In terms of sophistication when it comes to cloud computing, Etelos is surprisingly pretty well ahead of just about anything Microsoft, Google, Salesforce or Apple.

For example, Etelos already offers a synchronization service that allows people to share data across multiple sets of applications, which is something Microsoft is currently trying to build out. It already provides the ability to integrate with Google applications, which is something that Salesforce.com just announced it will offer on its Force..com cloud computing service. And Etelos has a CRM application that synchronices with the iPhone from Apple.

All of this works because each application set up on Etelos share a common middleware framework that Etelos built by leveraging WebDAV, which stands for Web-based Distributed Authoring and Versioning, WebDAV is an extension to HTTP that allows user to edit and manage files remotely.

What's amazing is that not only has WebDAV has been around since 1996, but just how few companies have taken advantage of it to deliver shared services. Of course, now that everybody vendor wants to be a provider of cloud computing services, they seem to be busy creating their own proprietary implementations of what WebDAV essentially does. That, unfortunately, may turn out to be a real shame when it comes to interoperability across different clouds. So before that happens, maybe it's time to take another look at WebDAV as a foundation for shared services across multiple cloud before we waste another 10 years talking about the need for cloud computing interoperability when much of what we need to deliver that is already here.