This Ikea clock was modified to display my location for my family at home. It is nice that they can check up on me without checking online. The kids are especially enjoying it.
I use 5 different geofences in an iOS app, monitoring entrances and exits for key points on my daily commute (and the bay area as a whole). The app reports the triggers to a Google App Engine app. The minimal time allowed by iOS is enough to get the call through to the server. GAE then passes the events onto the clock via the iDigi web service.
Inside the clock, I use a Fio and Xbee radio paired to my ConnectPort x2. iDigi is able to push messages through the ConnectPort to the Xbee and update my status.
Original project date: Dec, 2012.