Phone

The iPhone allows conferencing, call holding, call merging, caller ID, and integration with other cellular network features and iPhone functions. For example, a playing song fades out when the user receives a call. Once the call is ended the music fades back in.
The iPhone includes a Visual Voicemail feature in conjunction with AT&T which allows users to view a list of current voicemail messages on-screen, without having to call into their voicemail. Unlike most other systems, messages can be listened to in a non-chronological order, by choosing messages from an on-screen list. AT&T modified their voicemail infrastructure to accommodate this new feature designed by Apple.
SMS messages are presented chronologically in a mailbox format similar to Mail, which places all text from recipients together with replies. Text messages are displayed in speech bubbles (similar to iChat) under each recipient's name