Google has updated it's search app with voice search. Immediately, it is being compared to Siri. You can ask Google Search different questions and depending on the question, it will present you with the answer, search results, and even video. Along with the Siri comparison, Google Search currently cannot control other apps. That's not to say it won't happen in the future. This app works on the iPhone 4 which Siri currently does not support. It is also said to be faster than Siri.
So once again, the competition is heating up. This is usually good for users because we get great products out of friendly competition. If you don't have this app, it may be worth a try. Then let us all know how well it works.