Google has released a major update to their Google Mobile App for iPhone with a nifty new feature that you'll see geeks demoing at parties for weeks to come. That feature is voice recognition. Launch the app, hold the phone up to your head, speak your search query, and in about six seconds you'll have a list of results. If your query is location-relevant, like, per se, "sushi", you'll be given a list of results that are closest to you. Beyond the voice features, the location-awareness is also unique to the app, as a Google search in Safari has no way of knowing your location. Also, the results page that it returns is better formatted for the mobile screen than searching in the browser.
Is it gimmicky? Somewhat. Is it faster than typing? Generally yes. How well does it work? Acceptably well. Andy Baio of Waxy.org attempts to deconstruct how the voice recognition works. The recognition happens server-side, with the app seemingly sending only 100-300 _bytes_ of pre-processed data.
In my testing, the app worked well with common terms, place names, and names of notable people. Being Google, you can also use it for unit conversions like "100 Canadian dollars in US dollars" or "50 miles in kilometres". Fans of the Simpsons will be amused that it took two tries to get "beat up Martin".