Although Apple has not traditionally provided any details about the suppliers accompanying it on the iPhone, some analysts seem to have been able to get detailed information about the phone component manufacturers.
Among the most prodigious of details is FBR Research, which has compiled a comprehensive list of suppliers. At the top of the list is Samsung, which is responsible for producing the main chip, the one that runs the applications and the video processor, Infineon produces the baseband chip, Marvell the one for Wifi, Unimicron and Tripod take care of the printed circuits, the Broadcom touch screen processor, Cambridge Silicon Radio specialist Bluetooth chip, Entery Bluetooh module, Foxconn takes care of assembly and mechanical parts, Cheng Uei of connectors and wiring, case catcher, Largan Precision produces the lenses of the camera while the module of the same Altus camera. The touch screen, instead, of the German Balda AG.
During the day yesterday, on the basis of some information from Germany, there was a rumor that the main processor of the iPhone was from Intel. Intel itself, however, has flatly denied the rumor.
[update: Marvell's iPhone processor: see this Macitynet page]