I'm looking for an app that will transcribe speech into text that I can use in the car, i.e., something where I can just tap the app and begin talking.

This would be preferable to, say, opening AK Notepad, tapping "add note", tapping the keyboard icon by accident, tapping to bring the keyboard back, tapping the mic icon and, finally, smashing my car into a tree. :-)

Anyone know of an app that does this?