They could take the valve approach

  The fact that everyone is always moving around within the company
  makes people hard to find. That’s why we have http://user—check it
  out. We know where you are based on where your machine is plugged
  in, so use this site to see a map of where everyone is right now.

http://www.valvesoftware.com/company/Valve_Handbook_LowRes.p...