Amazon has posted a YouTube video demonstrating the use of the button.
My first reaction: how long will it take for the maker/hacker community to figure out other uses for this button?
My second reaction after watching the video: I could use this.
So I requested an invite.
Amazon is also pretty, um, curt with their terms and conditions:
There is no indication as to how the button press translates into the order, but using the Google patent search I found this little gem, which describes using SMS messaging to complete "one click" orders. I'm guessing that's what we have here, a tiny cell transmitter, very difficult to modify and use for other purposes.