It is finally going to be possible to transfer MMS messages between U.S. carriers.

Yes, X.400 is finally here.

X.400, I should note, was an interoperability system for moving messages betwen X.25 networks, and for billing the costs through the carriers. It took years to negotiate, it was difficult to implement, and it was made obsolete by the Internet's basic agreement to move the bits first and settle later.

Today's mobile or cellular operators (take your pick on the name) are much like the old X.25 operators, such as GEIS and CompuServe. The networks they operate are walled gardens, very proprietary, so it takes both technology and diplomacy to get stuff over the walls.

This is not cool, once customers start taking pictures with their camera phones and (under operator urging) want to share them.

Why do operators want to replicate the failed past? Because they think they can prevent the creation of a real Internet in the mobile world, and continue to charge per-bit.

Thus, while you will be able to move pictures off your mobile phone, it's going to cost you. This fact should keep stand-alone digital cameras viable for years, even if camera phones become equally feature-laden.

The news here is that Mobile 365 has signed agreements for transferring photos and other big files between the two major U.S. carriers, Cingular and Verizon.

Mobile 365 offers what it calls an operator charging gateway, which means it can handle the billing on data transfers between networks.

The result is called MMS interoperability, but it comes at a price set by operators.

Camera phone users can expect some nasty surprises in their mobile bills over the next few months, because if there is consumer training on this I'm sure it will involve only the technology, not the cost.

Still, for anyone involved in content, or moving content, over mobile networks, this is a red letter day.