This goes on our desert island web pages list. That's it--totally plain long list of tools with boring little descriptions way down there below, but it's one of my favorite pages on the web. Why? It embodies the awesome power of the simplest and most ubiquitous web tool in the world: Google's search. Every last one of these tools starts from the same place: that text input with the button that says "Search." Every possibility explodes out from that interface and it does so fast.
Let's look at some of what you can do:
- Books
- Cached links
- Calculator
- Currency Converter
- Definitions of words
- Product search
- Images
- Local business
- Movies
- Q&A
- Search by Number
- Site Search
- Stocks and Quotes
- Travel Info
- Weather
- Web Page Translation
And even that old standby, "I'm Feeling Lucky." We bet you didn't know about half of those, but give some of them a try. Prospective homebuyers, try typing, "1/3 acre in square feet" and see what it returns. Expecting a shipment by UPS or Fedex? Try typing your tracking number into Google instead of fumbling around on those other sites. Want a night out at the movies? Don't start at Fandango, just type in "Juno" at Google and you're on your way.
The fact that all of these technologies can work from the same interface is a major engineering feet. Google's Search technology is incredibly effective at inferring context based on the language of the little string of text you type into that field. Now none of this is news, but this unassuming page tucked deep within Google's Help section reminded me today of 
the depth and simple, clunky beauty in the design of the web's most successful interface.
Go see Google Web Search Features for yourself and play around.