Summary
The release of the Voice XML 2.0 standard has been instrumental in giving developers a cross-platform way not only to build stand-alone voice applications but also to integrate voice into a broad range of web service–based applications.
Harnessing the speech recognition and text to speech technologies available from voice providers, Voice XML enables developers to build powerful voice-controlled apps by defining their own domain-specific grammars by writing their own application-specific JavaScript and by submitting data from Voice XML to server-side gateways that can establish connections with any other server or web service available across the Internet.
It remains to be seen how Voice XML will ultimately play in the Web 2.0 space, but if you come up with any interesting mashup combinations, I’d be happy to hear about them.