Google at their search conference today have announced that they will be displaying answers to search queries at the top of the search results. This is direct competition to Wolfram Alpha who offer a similar but much more refined service that this.
However, Google will give you quicker results for queries such as "Who was the inventor of telephone", "When will this movie release" and so on.
I had discovered this feature quite sometime back and had written about it as Google Testing Answering and feedback system in late June. The service is definitely useful and provides direct answers to several questions, making Google a one-stop for almost everything you want to search for.