TextAloud: In 2004 I posted an entry about this application. "TextAloud MP3 is Text To Speech software that uses voice synthesis to create spoken audio from text. You can listen on your PC or save text to MP3 or wave files for listening later."
Just as an update, this week's WinXP News says: "TextAloud is the world's leading text-to-speech program, available now with optional AT&T Natural Voices for the best in computer speech. TextAloud uses voice synthesis to convert text into spoken audio. Listen to text from email, web pages and documents on your PC or create MP3 or WMA files for use on portable devices like iPods, PocketPCs, and CD players. Imagine being free to relax, get up and stretch, or work on other things while the information you need is read to you in a pleasant, natural sounding human voice. Better still, leave your computer behind. TextAloud can save your daily reading to audio files for your portable player."
NextUp.com, makers of the above software, offers several other tools for text-to-speech.