Use Quick Responses with Google Voice One of the most useful features introduced in Ice Cream Sandwich is "Quick Responses": the ability to send a default SMS message to the caller. "Can't talk now. Will call you back." etc. 

However, I'm 100% Google Voice. I only ever give out my GV number, and I don't want to broadcast my actual cell phone number by using a Quick Response. 

Is there a way to use them with Google Voice?
This is apparently not currently possible.

I'm not the only person with this desire. There's an open issue at Google (Issue 23176).

In one of my searches, I found someone who says they looked into the code for the Phone app, and found that it's calling the Messaging app directly without allowing the Messaging Intent, which is what would prompt me to choose the Messaging app versus Google Voice to send the message.

The app suggested by dymutaos looked somewhat promising, but I am concerned about its security.

So, unfortunately, this very useful feature is currently useless to me. I hope they fix it in the not-too-distant future.