Wolfram Alpha is a new search engine. But don't think of it like another company trying to compete with Google. They are not in that kind of search business. Basically it is an information quick return system. Type in something you want to know. For instance, I typed in Methanol. At my last job we were often calculating the molecular weight of methanol based compounds. We had to look up its molecular weight all the time. Through Google you would find a list of websites with information about methanol and then open one up to find what you need. With Wolfram you don't get a list of websites. All you get is the information. It's really simple.
What I found to be really cool was the results it returned from the query: Life, the Universe and Everything. Try it.
Unfortunately this product is limited in its uses. There were a lot of results that it couldn't return yet. I searched, trying to be clever, WolframHart. It didn't understand. But then again it is pre-Beta.