A few days ago Google announced that they begin to experiment with text-to-speech on their “Knol”. Quote from their site: “We are experimenting with Audio Playback as an option for some knols, starting with a handful of English language featured knols. You can listen using our Flash player, or by downloading an mp3 file and using any mp3 player.” If a listen-button is shown next to the “print” and “share” button, you know that the Knol is available also as audio. Read all about it and try it out here: http://knol.google.com/k/knol-help/knol-audio-playback/