I want to have the mic listening for a keyword and then have it turn on Google recognizer? Has anyone been able to do this and how? Any advice would be greatly appreciated.
This is something added Android 4.3 and is featured on the Moto X. The phone passively listens all of the time for you to say "Okay Google Now" followed by whatever your command is. (There's a special low-powered CPU being used to listen, which is why it's not available on every device with 4.3.)
(Here's a video demo by Slashgear.)
I expect to see this more frequently as new hardware comes on the market.