UPDATE: October 1st, 2012
I noticed that the code doesn’t work anymore, since they’ve added a crossdomain reference and modified the API a bit, but a simple proxy should do the trick, check this blog for solution.

I’ve just discovered an ultra-simple way of converting text to speech utilizing an undocumented Google API code.

import flash.media.Sound;
import flash.net.URLRequest;

var _path:String = 'http://translate.google.com/translate_tts?q=';
var _sound:Sound = new Sound();

// all it takes is just to pass the words to the path						
_sound.load(new URLRequest(_path+ 'hello world'));
_sound.addEventListener(Event.COMPLETE, soundLoaded);

function soundLoaded(e:Event):void
{
	_sound.play();
		
	_sound.removeEventListener(Event.COMPLETE, soundLoaded);
	_sound = null;
}

It’s limited, yet the practical uses of it are endless.

Here’s a little demo.