Anyway, here's a teaser of Nerd's awesome recipe:
what we want to do is examine some ways to integrate the Google Voice feature set into our existing Asterisk implementations. The potential benefits are enormous. There's free calling in the U.S., free distribution of inbound calls to multiple phone numbers scattered around the country, free SMS messaging and delivery by email, free transcription of voicemail messages into text-based emails, free conferencing, and free GOOG-411, a voice-activated service that let's you find nearby businesses by saying where you are and what you're looking for. For today, we've set our sights on the Google Voice feature set which is easiest to integrate into existing Asterisk systems: free voicemail message transcription, free calling in the United States, and free GOOG-411 directory assistance. For lack of a better term, we call it... Googlified Messaging™.
Well, what are you waiting for? Go read the entire recipe and tutorial. Great stuff!