Voice Search
Speak your search queries instead of typing.
Voice Search is a feature of Google Mobile App for iPhone, BlackBerry and Nokia S60 V3 phones.
If you have an Android phone, search for the "Voice Search" app in Android Market. The Android operating system also enables you to speak instead of typing in any app where you launch the keyboard.
Voice Search is not available in all languages or on all mobile phones.
via google.com