Google's Chrome browser for OS X has had the ability to do voice search for about two years now, but the latest version of Chrome appears to bring something a bit more Siri-like to the mix. Now, when you ask Google certain questions about the weather, sports scores, stock prices, directions and calculations, you get a spoken answer.
The latest version is 27.0.1453.93, which you can update to by selecting About Chrome from the Chrome menu, and approving any updates or restarting the browser if prompted. Once Chrome is up, head on over to the google.com search page and you'll see the familiar microphone in the search field (note that the mic does not appear in the Chrome "omnibar"). Click the mic, respond to any requests to let Chrome have access to your mic and video camera and then start asking questions.
The result is not quite the conversational search that was touted during the Google I/O keynote last week, but it definitely shows the direction that Google is heading and it's bringing a bit of Siri-like functionality to OS X before Apple does. The video below demonstrates several of the searches that I performed -- it's all done in real time, so you get to see the failures as well. The current release seems to have a tendency to display "No Internet Connection" frequently, a problem that reloading the browser will fix. By the way, if you've used the mobile version of the Google search app, this will all be familiar to you.