If you didn't know already, Google announced Google Now in their I/O event recently. It's part of Android Jellybean and has been made to go up against Siri. Google were first to come up with voice search, Apple took the idea and took it to another level, now Google has taken it up another level beyond that.
The video below is a great demonstration of the two voice search engines up against each other, and the clear winner is Google Now. It absolutely tears ahead of Siri. Jon, the man behind the video, says that Siri makes search results look better, I disagree. I think, Google does a better job, and it also saves those searches for when you want to go back to them.
I feel sorry for Samsung. S-Voice, which is a Siri contender by Samsung, came with the Galaxy S3 and was one of the killer features. But Google has come along and completely blown it out of the water. Hopefully though once the Jellybean update comes to the Galaxy S3, S-Voice will be banished.