Siri, however, is nothing like typical Google voice-recognition for search.
Siri starts with voice recognition, but then applies machine learning from your previous requests (and from your contacts listing) to "understand" with context what you are probably wanting to find out.
So you can ask, "Do I need to buy a snow shovel before tonight"?
Siri is a product of SRI (Science Research International), which has invested more than 20 years and hundreds of millions (from military funding and DARPA) to understanding voice communication semantically.
I think I mentioned it before, now that I think of it; and so you know what I am talking about.
It's going to be interesting if SRI is able to learn from your search and the billions of other search requests it gets. It will learn when it gives you the wrong answer, and you note tell it so.