One of the cool things I've just found on the Intervoice developer portal site is a sample application they have recently put up. More details (including the phone number to call) are at

You can dial into it, give it a zip code (or city/state) and it will return the nearest ATM or bank information. It's currently running on beta software and so is occasionally unstable or unavailable - but it really is a live running SALT telephony application. This stuff isn't vaporware any more!

The application is a good example of what's possible, but there is probably still some room for improvement. There seemed to be a couple of places where synthesized speech is used where I'd expect a recorded prompt. There's also an audible click at the end of each prompt which I'd hope that they will be able to improve upon. Certainly our internal applications don't seem to exhibit this behaviour. All the same, it's a good solid demonstration.