on-wall indoor microphones in the home?

I'm curious about what folks have tried using for doing voice recognition in rooms.  What's worked and perhaps more importantly, what didn't work (and why).
 
There's a whole range of potential issues surrounding VR, but I'm mainly asking about good overall pickup of voice for control purposes in a residential setting.
 
I'm not asking about dealing with start/stop, or the hardware interface involved.   Just about the type of mics and what did/didn't work effectively for indoor use in a home setting.  Not outdoor, not intercom, just 'hands free' use.
 
The whole VR command recognition, start/stop, key phrase, etc, are all fodder for different threads.  They're certainly non-trivial issues.  But none of which would be relevant without having a reasonable means to deal with obtaining the audio in the first place.
 
Anybody care to comment?

I have lots of experience on what DOESN'T work.  I always used very high quality CROWN MB microphones and had echo cancellation as well. 
 
While voice response and microphones seem rather simple, and the technology has come a long way, it has a way to go. The fact that you are a distance from the mic is the biggest problem, as sound changes over a distance and echoes increase. In addition, other noise, such as just a TV running or any sound can be picked up as well.  Then there is the problem with multiple mics together and how they are gated.  In the end, it was much to much work for the reliability I eventually obtained. It will be a few more years before the Jetson's are here.

This being why I asked: http://cocoontech.com/forums/topic/26420-jasper-voice-control-on-a-raspberry-pi/