Google's Chrome browser passes anything you type into the address bar that isn't an obvious URI on to the default search engine.
While web browsers should have some built-in smarts, they can never match the collective intelligence of a worldwide search engine. For example:
weather San Francisco
san francisco 49ers
10.5 cm in inches
Italian food 02138
homes Los Angeles
150 GBP in USD
american airlines 18
510-525-xxxx (I'm hesitant to link a listed personal phone number here, but it does work)
I like to think of the web browser address bar as the new command line.
"plants vs. zombies" daterange:2454955-2454955
filetype:pdf programming language poster
Any command line worth its salt has some kind of scripting language built in, too, right? No sweat. Just try entering this in your browser's address bar.
Apparently we've spent the last 20 years reimplementing the UNIX command line in the browser. Services like yubnub make this process even more social, with collaborative group creation (and ranking!) of new commands. You can find some of the cooler ones on the golden eggs page.
Honestly, I was never a big command-line enthusiast; even way back when on my Amiga I'd choose the GUI over the CLI whenever I could. But maybe I bet on the wrong horse. Perhaps the command prompt – or more specifically, the search oriented, crowdsourced, world public command prompt – really is the future.