In libraries we worship interoperability, in the abstract at least. We believe it is an unalloyed good.
My snappy interoperability tag is "recombinant potential": things are interoperable to the extent that they are capable of being combined or recombined with other things.
We are traveling with a laptop, head phones, two cell phones, a Blackberry, a digital camera and three iPods (two Nanos and a shuffle). I am sure that there is other stuff I am not remembering or do not know about ;-)
This requires us also to carry a variety of chargers, and, as they are US devices which we want to use in Ireland, a couple of adapters. Can we mix and match these, combining chargers and devices? Using headphones with the cell phone with music on it? Of course not, or only in limited ways.
I mentioned the other day that I had left my laptop cable behind. Can I borrow somebody else's laptop cable? Of course not. And we need to find another way to charge the iPods.
Sure, there is a small industry creating various 'recombining' devices, but this requires additional thinking and investment, something we are not organized or inclined to do.
Now, I am sure that I could rustle up a literature on the economics of all of this, suggesting why vendors are interested in this level of lock-in. But for the moment, I just wish that their recombinant potential were higher, reducing our traveling clutter and increasing our convenience.