A first communication device is detected as being substantially collocated with a second communication device using a short-range wireless network. A connection is established between the first and second communication devices over the short-range wireless network. In some instances, authentication data can be sent from the second communication device to the first communication device to authenticate a user to the first communication device. Further, input is received from the first communication device over the short-range wireless network specifying a telephone number for a telephone call using the second communication device. A connection is established between the second communication device and a cellular base station to initiate the telephone call with a third communication device associated with the telephone number. In some instances, the second communication device is a wireless headset device.