So I was sniffing around Google, looking for something interesting to read, and came across this article at a place called ネットマニア(NetMania). It would appear that Pentax are in the process of developing a very good, natural sounding text-to-speech engine. And here I thought all they did was make cameras — as it turns out, they may be planning to integrate it into digital cameras in some way, and of course they could license the technology. Anyway, you can test drive it here at the Pentax website. Just copy and paste some Japanese text into it and be amazed…Or, impressed; the engine does make occasional mistakes (like reading “先ず(まず)” as “さきず”), but those are forgivable, and it does sound pretty good. It might be of some use to you in practicing Japanese.