Yes, you can now easily add speech to your blog, and its free.
Just sign up for it at Odiogo.com.
I use it on this blog. To try it, click the small box labelled "listen now" just below the subject of any blog post. (It takes a little while for Odiogo to process the blog post and convert it into an MP3 file for streaming or downloading, so if you happen to try this just after I've written the post, it might show a message saying "not yet available for listening" - in that case, just try somewhat later - it should work.) Yes, it creates an MP3 file, so not only can you listen to the post once, but if you want, you can save the MP3 for listening to later.
I found the quality of the generated audio to be quite good for text-to-speech or speech generation, as it is called. This is a difficult area, so the Odiogo.com results seem to be quite good, given that. The voice sounds like a real one, except for a few mispronunciations now and then, which are mainly due to abbreviations / acronyms - I guess it would require AI (Artificial Intelligence) to solve that, and even then it might not always work, because people keep on creating new ones.
BTW, you're reading this and know of any free and open source (or even free and closed source) speech-to-text / speech recognition software library (that can be programmatically controlled), please leave a message in the comments or better still, please email me. I'm interested in developing an application for personal productivity use, using such a speech recognition library.
Vasudev Ram - Dancing Bison Enterprises