A mobile communications device adjusts a level of friction between a surface of the device and one or more other objects that may be in contact with the device, such as receipts, credit cards, keys, money, the user's hand or fingers, and the like. To adjust the friction, the device first determines its current environmental context, such as whether it is inside the user's pocket or lying on a table surface, for example. Then, based on that context, the device varies a coefficient of friction to increase or decrease the friction between the surface of the device and the surfaces of the other objects. Varying the friction allows a user to grip the device easier and/or reduce the chance that the other objects in contact with the device are also inadvertently removed from the storage location with the device.