After posting that last entry I went looking for the latest version of app_swift but the latest maintainer's site seems to have disappeared and nothing was ever checked into the repository on sourceforge. I've put up app_swift-1.6.2.tar.gz on my download site as a courtesy.
I have a bit of a rewrite and improved code that I started a few months ago that I will eventually post when I get some time to test it out further.
I've been meaning to write about this for a while.
Whatever you do, do not purchase Cepstral Voice Starter pack from Digium's online store. For starters, I found out after purchase I might add, that at the time (a few months ago) and currently (from the periodic support ticket reports I keep getting) that their proprietary binary blob text-to-speech module (which they force you to use) doesn't work with Asterisk 1.6. (There was no mention of the fact, or versioning info on their storefront).