Last week, Adafruit published a tutorial on how to get Google Glass to communicate with hardware  and the internet via the Pi. Using XMPP (which the decrepit and elderly, like me, may recognise as what used to be Jabber), you can use Google Glass to talk to a Pi, which can then send instructions external devices, or stuff on the internet.

See original here:
Wearables: Google Glass, and something quite different