My AirPort supports several computers, my wife's IPod, and an expansion node. I don't know how it sorts everyone out. My cell phone hooks up to a hands-free setup in my van when I get into it, and the van has its own WiFi which it somehow pulls out of cell signals and who knows what when I'm travelling. Google broadcasts its own WiFi signal for free from the streetlamps near here.

My cell phones talk to thousands of towers and work out how to move conversations between them. This happens even as I drive around, moving from cell to cell.

Phones, cars, and wristwatches all talk to GPS satellites to place themselves on the planet.

My clocks listen to something in Colorado which tells them what time it is.

Neighbors get their TV, internet, and maybe even phone service from a dish on their balcony talking to a satellite in geosynchronous orbit.

That's just stuff I'm associated with personally.

Magic.