"That's just the final output device. But how does my imaging get to you almost wherever you are?" He looked expectantly at Juan.

C'mon, Bertie! But aloud, Juan said: "Okay, that's the worldwide network."

"Yeah, you're essentially right, though the long-haul networks have been around since forever. What gives us flexibility are the network nodes that are scattered all through the environment. See, look around you!" Bertie must have pinged on the sites nearest Juan: There were suddenly dozens of virtual gleams, in the rocks by the road, in the cars as they passed closest to him, on Juan's own clothing.

Bertie gestured again, and the hills were alive with thousands of gleams, nodes that were two or three forwarding hops away. "Okay, Bertie! Yes, the local nets are important."

But Bertie was on a roll. "Darn right they are. Thumb-sized gadgets with very-low power wireless, just enough to establish location—and then even lower power shortrange lasers, steered exactly on to the targeted receivers. Nowadays, it's all so slick that unless you look close—or have a network sniffer—you almost can't even see that it's going on. How many free-standing nodes do you think there are in an improved part of town, Juan?"

That sort of question had a concrete answer. "Well, right now, the front lawn of Fairmont schools has ... 247 loose ones."

"Right," said Bertie. "And what's the most expensive thing about that?"

Juan laughed. "Cleaning up the network trash, of course!" The gadgets broke, or wore out, or they didn't get enough light to keep their batteries going. They were cheap; setting out new ones was easy. But if that's all you did, after a few months you'd have metallic garbage—hard, ugly, and generally toxic—all over the place.

Juan abruptly stopped laughing "Wow, Bertie. That's the project? Bio-degradable network nodes? That's off-scale!"