Amazon's has created a very clever and useful Dash Button gadget for easy re-ordering.
The communication protocol is based on WiFi, and somebody already figured out
how this could be intercepted to reuse the button for other purposes,
by just configuring router differently, and then respond to event locally.
This may be an opportunity for Amazon (or somebody else?)
to sell similar buttons with SDK as a general purpose IoT tool.
There will be many places where this could be very useful.
How I Hacked Amazon’s $5 WiFi Button to track Baby Data — Medium
mentioned on podcast: Intro to Node.js - MS Dev Show Podcast