A mobile telephone comprises a telephony unit to process wireless telephony signals and a browser to enable the user to navigate hypermedia information via a wireless network. The telephony unit receives a signal indicating an incoming telephone call with Caller-ID information. The telephony unit provides the Caller-ID information to the browser, which uses the Caller-ID information to identify an action or data previously associated with the Caller-ID information. In one embodiment, the browser looks up ring tone data associated with the Caller-ID information and provides the ring tone data to the telephony unit, which causes a ring tone to be generated based on the ring tone data. Distinctive ring tones may be associated with particular callers or groups of callers. The browser may request ring tone data from a remote server over the wireless network.