News: yRead version 3 is out for XP & Vista users. Details here
yRead2 will load a plain text (TXT) or HTML file and display it in a single-column, resizable window. Then it will read the file to you out loud, using human speech. You can even get voices for other languages (see the yRead links page for details) Use it to listen to ebooks, your own writing or any other piece of text.
By default, yRead2 uses the Microsoft SAPI 5.1 speech engine with a couple of voices which sound like constipated robots. The good news is that if you purchase and install one or more AT&T Natural Voices, they'll be available in the yRead dropdown menu. (I bought mine from the TextAloud website.) You can also use the neospeech voices with yRead2, as confirmed by a user.
yRead2 now includes a catalogue screen for the online Gutenberg archive - it will retrieve the latest catalogue, show you a sorted list of all titles and allow you to pick, download and listen to any of them.
If you want to stream the speech from yPlay to an MP3 file, check out HardDiskOgg. It'll capture any sound you can hear on your PC and can store it in a range of formats. One-stop audio books, here we come.
If you're looking for a similar tool for Linux or OSX, try festival KDE on Linux contains several programs with text to speech interfaces.