You’re elbow-deep in your turkey, ready to start the stuffing and you need to calculate how many ounces of walnuts are in a cup. This year, rather than stopping midway through to wash your hands and type in a search, you can just speak: “Ok Google, how many ounces are in one cup?” Et voila. You can also say “Ok Google, set a timer for 30 minutes” so you don’t forget to baste that turkey.
Under normal browsing circumstances it’s not entirely hands free, though, as the active tab in Chrome needs to be Google.com or a search results page for it to work. With Android 4.4 on mobile devices you can bring up the voice search interface by saying “Ok Google” within the home screen, while the Moto X has special hardware that enables always on listening (even with the screen off) to quickly activate voice commands.
Google will likely be expanding the capabilities of the voice search extension going forward. For now, this is limited to the English language and only works in the U.S. version of Google.com.