Welcome to Vox Machina, the voice of the machine. Vox Machina is a web application that can convert your text input into a spoken word MP3 file. This conversion takes place on-the-fly using Apple's Mac OS X speech synthesizer and the open-source LAME audio encoder. A Mac OS X desktop application is also freely available.
I tried it out and it is indeed a joy. Listen to what it can do to my newest addition to the Living Bible, from the Book Of Peter....Cottontail: