1. A method for selecting a function to be executed on a mobile device, the method comprising: collecting, by the mobile device, proximity data that indicates the mobile device is proximate to a user; collecting, by the mobile device, acceleration data; determining, by the mobile device, which ear of the user is proximate to the mobile device using the acceleration data; and in response to determining which ear of the user is proximate to the mobile device using the acceleration data, selecting, by the mobile device the function to be executed, wherein the function selected varies based on which ear of the user is proximate to the mobile device.