iPhone Built-in Accessibility

Accessibility comes standard on iPhone 3GS. From closed captioning to TTY
support, Apple builds accessibility right into the iPhone operating system.
And innovative new features on iPhone 3GS take accessibility a step further,
right out of the box. 

Features: Voice Control, VoiceOver, Zoom, White on Black, and Mono Audio.

For more information browse to:
http://www.apple.com/iphone/iphone-3gs/accessibility.html

Links:
Accessibility Solutions for iPhone
http://www.apple.com/accessibility/resources/iphone.html

Vision
http://www.apple.com/accessibility/iphone/vision.html

Hearing:
http://www.apple.com/accessibility/iphone/hearing.html

Physical & Motor Skills
http://www.apple.com/accessibility/iphone/physical.html