Sfxr (and also Bfxr) is a great tool for generating sound-effects for games. Is there something like this for speech synthesis?
Not every game development tool and platform has a speech synthesis engine, and it would be great to at least get some decent-sounding placeholders in place to see how the usability/experience plays out. Even better if the results are tweakable, like sfxr.
I'm looking for something I can at least run on windows, though preferably (like Bfxr) I would like a web application that I can just run out of my browser.