I've been trying out Tony's xPL Proximty app and it's been working out pretty well. I was using a Java based blueooth app but I like Tony's app much better. With the USB bluetooth dongle in the server room, the range isn't very good, so I made a USB Cat5 extension. I cut a USB extension cable in half and terminated each end with a Cat5 keystone jack such that each wire took 2 connections in the jack. I connected the jacks with a 25 foot patch cable, plugged one end into the server and a powered USB hub into the other. Finally, I plugged the dongle in and it worked. Coverage was much better but I'm thinking of moving the dongle downstairs to be closer to the phones and that may be a little too far for this hack. There are some USB extenders I may look into later.