I figure everybody is tired of reading about solar and wants me to get back to automation stuff. I'm releasing BlueTrackerScript, an app that I use at work to tell if I'm at my desk (this affects forwarding for Google Voice Automation). Of course, you'll need a bluetooth adapter for your PC, leaving bluetooth running on your cellphone, and you'll need to add some actions to the included sample script, blue.js.
Since I use this on my work PC, I want it to be able to communicate with my home server without any interaction necessary (setting up ssh tunnels, etc.). So I created two special URLs on my public webserver, one for detection and one for timeout. The script will fetch the appropriate URL using Wget. On the webserver, it watches the access log for access to those specific URLs from a specific IP address (my work IP), and passes a message to the automation server if it detects those URLs have been accessed. The automation server then adjusts Google Voice forwarding.
BlueTrackerScript is available here.