There is also software you can use that monitors for Bluetooth devices and can perform actions based on them. Makes it very easy to roll your own piece of software and not have to trust a 3rd party device: <a href="http://www.macupdate.com/app/mac/23858/proximity" rel="nofollow">http://www.macupdate.com/app/mac/23858/proximity</a><p>I am not entirely sure why you would need a dongle over a phone. Perhaps the the creator can chime in here and explain to us why we would chose a hardware device over what we already have in our pocket?