Siri can find information in Wikipedia, Yelp and Wolfram Alpha. It successfully answered when I asked it, Whos the president of Iran? (though it misunderstood me the first time) and Who stars in Boardwalk Empire? When I asked for a French restaurant in Bethesda, Maryland, it instantly returned a list from Yelp, ranked by user reviews.
In my tests, I was able to dictate emails and text messages, even in the car over Bluetooth, without looking at the screen. Accuracy wasnt perfectabout 20% of the time I had to try twice to get all the words correct. But, in most cases, Siri didnt make more errors than I do typing on a virtual keyboard...
The system understands multiple, colloquial forms of a question. I asked, Will the weather get worse today? and Siri answered, I dont think the weather is going to get worse and displayed a weather chart. You can check stock prices, addresses, map directions and much more. It also answers in a friendly fashion, saying things like Coming right up or Im not sure what you said, Walt. And it has some cute answers built in. When I asked it Whats the best phone? it said, Wait
there are other phones?