Interesting article about neural network research out of the Google X lab. They used 16,000 processors to be able to compile the concept of 'cat' without supervision. Actually, not that easy of a task. The article mentions that this success is great for the field of speech recognition.

http://www.nytimes.com/2012/06/26/technology/in-a-big-network-of-computers-evidence-of-machine-learning.html