Preparing for the first-ever Mobile Internet World in Boston this week (www.mobilenetx.com), I was thinking how limited in imagination much of today’s mobile internet really is. A two-dimensional world — flat.

When I first saw a WAP-enabled phone that could check flights on a Lufthansa web site (2000?), my brain exploded. I thought, now here’s a technology that’s going to really change everything — again. But it hasn’t, yet. Too many obstacles: high cost and low speed for most consumers, thorny development issues for those who’d do useful things for us, and of course the closed mobile ecosystem.

A 3D mobile internet would be full of life, pizzazz, value… dimension. Not connecting just with flat screens of stuff, but with objects using the Anywhere Network to become more useful to their owners.

Here’s a heartening example, though, that I just found: the Eye-Fi wireless photo card for your camera. Check out www.eye.fi for details. A simple photo card that fits the SD format for cameras has a built-in Wi-Fi transmitter and, once it’s configured, can upload your photos from your camera to a photo website such as Flikr. Skip the PC, skip the website login, just make it happen automagically. That’s three-dimensional thinking, putting the mobile connectivity directly into the device.

The mobile internet will explode once developers and consumers can think in three dimensions, not two, about how to use connectivity to make mobile devices — not just phones — smarter and more useful.