Previously, previously, previously, previously.
Almost as good: The Windows version.
Both the Android and Windows ones are awesome, but I gotta admit Windows just gives you so much more scope.
Someone else who reads The Old New Thing, eh?
That basically happens already with people staring at their phone.
Now imagine the people who use their phones while driving using these AR goggles instead. Perhaps "innocently" as an AR satnav until they notice that Stephen Fry said something clever on Twitter.