To describe the various projections of ourselves into cyberspace, I use the following metaphor: we’re cells, and we’re growing the surface area of our cellular membranes. Every time I write a blog item, or post a Flickr photo, or tag a resource in del.icio.us, I enlarge the surface area of that membrane. I do it for two reasons. First, because I want influence to flow from me to the world. Second, because I want influence to flow the other way too. I’m soliciting feedback and interaction.

I monitor that feedback using an array of sensors that works surprisingly well. All of the parts of my public membrane can be instrumented with RSS feeds. By tuning into those feeds, I know — fairly immediately and comprehensively — who has touched which parts of my exposed surface area.

What I can’t do very easily, though, is visualize that entire complex surface. If somebody reacts to something I published years ago on some site I’ve forgotten about, I’m reminded that part of my surface area extends to that site. But it’s only a reactive thing, there’s no proactive way to review the totality of my published corpus. That’d be handy.

It’d be even handier for the parts of my membrane that aren’t fully public. The lack of such a capability, in those cases, is what makes security so hard for people to manage.

For example, I’m still working through the implications of the calendar cross-publishing arrangement I’ve set up for myself. Consider my Outlook calendar. It’s shared within the company by virtue of a default policy that I can view, or modify, by right-clicking the calendar in Outlook and selecting Properties -> Permissions. But it’s also shared with my family by way of a private URL that I created on my WebDAV server and transmitted out-of-band. I can see that private URL by right-clicking and selecting Publish to Internet -> Change Publishing Options, but there’s no indication there of who I gave the private URL to.

This example is just one manifestation of a general problem that cuts across all systems and applications that enable people to selectively expose surface area. There’s no unified way to see and explore that surface area. You have to make a mental inventory of all of the bits that you’ve exposed, you have to individually review the scope of visibility for each bit, and then you have to synthesize a view of what’s visible from a variety of perspectives. Humans are lousy at this kind of thing, computers are good at it, but we haven’t figured out how to enlist the computers to help us to it.

We can at least dream about how a surface-area viewer would work. You’d point it at a blob representing you, and zoom in to resolve the various bits of exposed surface area. There’d be a viewer-impersonation knob that would start at Everyone but could be spun to any of the groups or individuals to which you’ve granted permissions using any of your diverse permission-granting services. You’d spin that knob from one setting to another, and fly around exploring who can cross various parts of the blob’s membrane and who can’t.

I know this would impractical for all sorts of reasons. But I still want it.