The site I came across is http://www.odiogo.com/ and it says it converts text to speech on blogs. I have yet to try this but thought it looked interesting. I think it could be useful for making blog entries more user friendly for all of our students. I have a blogging assignment coming up soon and will try it out and post a followup but thought I would put it up here as well.
Info from the site:
Bloggers
Your posts where and when your readers choose! Turn your blogs into audio-to-go!- Your readers like your blog posts but may not have time to read them online?
- Reach hundreds of millions of iPod, MP3 player and mobile phone owners... anywhere?
Odiogo is compatible with all blog engines that publish RSS feeds such as Typepad, Blogger, WordPress or Overblog. Enroll in the service now and we'll let you know when the audible version of your blog is ready. The generated MP3 files are stored on our servers. You don't need to worry about technical integration tasks or bandwidth.