Google Android 1.6 (aka Donut), introduces accessibility features designed to make Android apps more widely usable by blind and low-vision users. In brief, 1.6 includes a built-in screenreader and text-to-speech (TTS) engine which make it possible to use most Android applications, as well as all of Android's default UI, when not looking at the screen. You can see this API in use within open source Android screenreader “TalkBack” –  when installed, standard Android user interface elements such as ListView produce spoken feedback during user interaction. Applications SoundBack (for producing non-spoken auditory feedback) and KickBack (for producing haptic feedback) generate additional augmentative output and demonstrate how multiple access applications can be active simultaneously.

Full Article: Open Source blog