We had it done in a couple of walls at our house because the corner of our house with two outer walls is our shower stall in the master and the pipes would freeze anytime it got below 10-15 degrees. We used USA Insulation and haven't had a problem since. It was so bad that we had the pipe burst the winter before, so we were not going to have that happen again. Sales guy came to our house and we worked down the price with him. It was a little pricey, but it was better than not being able to use our shower or paying for a plumber to come fix a broken pipe and then reinstalling drywall (that was not fun).
I would recommend them. Installers were a bunch of cool dudes too.
Video is a little cheesy, but gives a good explanation and animation.