What if the Romans had Wave?

Let me explain in a non technical way why Google Wave is a breakthrough. I argue that it doesn’t just revolutionarize the concept of email (only a few decades old), it changes the very concept of mail (thousands of years old).
Let’s go back in time and imagine the Romans had Wave. First of all, I argue that they would have called it Arbor, because it makes more sense and because they didn’t like oceans.
But what would it look like?
Let’s say you’re a Roman official working on a new taxation scheme for Lutetia (Paris). You would need some information from your colleagues over there and discuss a draft version. Normally you would have a slave copy the latest draft and have that copy sent by mail to Paris. There it is edited and a new copy is made, which is sent to you. And so forth.
But what if you are both making changes at the same time? In that case, your version has different changes than the version in the mail that is on its way to you. Your slaves will then have to combine your changes with the changes made in France and create a new version from it.
That’s a tricky business, especially when there is more than two parties involved. Each party would have to train their slaves how to do this. And if one party has an incompetent slave, there’s total chaos. No wonder the Roman Empire collapsed.
Then comes this crazy company that says: wait a minute, what if instead of sending a proposal directly to your colleague, you send it to us. This group keeps the proposal and sends a copy to your colleague After that, when either you or your colleague changes something, you send the new version to this group of slaves. They then send each participant a new document. And we’ll train our group of slaves to be extremely good at merging changes in documents.
And you don’t trust that company, there is nothing to stop you from training your own group of slaves. In fact, they’ll help you with it.