|Its hard to imagine how they can get away with calling these devices one wire when they have three leads.
The leads are power, ground and data. But, if you tie power and ground together, the device can store enough power from the data pin to both talk and listen when the data line isn't held high.
This is how I've come to package up these parts for distribution around my house. I've got a long run of CAT-3 bell wire running up and down the stairs. I cut into this and attached the one wire device with wire nuts.
To be clear: I'm running four wires around my house to connect to three pin devices completing a two conductor circuit called one-wire.