http://www.mousedown.net/mouseware/EventScripts.html
I highly recommend his for anybody using bluetooth detection on their apps. It recently replaced Proximity, as it allows multiple bluetooth devices and an adjustable amount of retries before timing out.
Between that and Smartphoneradar, my apartment knows when either my gf or i am are home. With a triggerlinc on the door, the apartment starts up based on who is in range and shuts down when nobody is in range.
It rules. Let me know if you run into trouble with the included library of example scripts, it took some tinkering to get them to work.