Apple iPhone/iPhone 3G (User manual) - Manual (Page 36)

Call someone in your contacts list Tap Contacts, choose a contact, then tap a phone
number.
Call a favorite Tap Favorites, then choose a contact.
Return a recent call Tap Recents, then tap a name or number in the
list.
Dial a number Tap Keypad, enter the number, then tap Call.
Jump to favorites from anywhere: Double-click the Home button.
Bring up the last number you dialed: Tap Keypad, then tap Call. Tap Call again to dial
the number.
Receiving Calls
When you receive a call, tap Answer. If iPhone is locked, drag the slider. If you’re using
the stereo headset, press the mic button to answer a call.
Mic button
Silence a call: Press the Sleep/Wake or either volume button. You can still answer the
call after silencing it, until it goes to voicemail.
Decline a call: Do one of the following to send a call directly to voicemail.
Press the Sleep/Wake button twice quickly. 
Sleep/Wake
button
Press and hold the mic button on the headset for about two seconds. Two low 
beeps confirm that the call was declined.
Tap Decline (if iPhone is awake when a call comes in).

Block calls and maintain Wi-Fi access to the Internet: In Settings, turn on Airplane
Mode, then tap Wi-Fi and turn it on.
36 Chapter 3 Phone