I was just thinking the other day that I could basically build my own Google Voice with Twilio. The transcription quality highlighting would be hard though. Even then, Google’s has some problems so they haven’t slammed the door on that one.
Twilio is a really great platform and I’ve been working on an IVR to put in front of my cell / Google numbers for a little while now. I love seeing the apps / mashups people are developing with it!
Keep up the good work!

Google Voice is making IVR concepts and programmability available to a much broader non-enterprise audience. The idea that normal consumers are put in control of when and where call gets routed is really powerful. While the underlying technology has existed for years, Google is taking that technology and packaging it in a way that makes it as accessible as GMail.
As an aside, Twilio will be presenting at both OSCON09 http://en.oreilly.com/oscon2009 and Astricon09 http://www.astricon.net/ talking about open source, Asterisk, and Twilio!