Voice Actions take speech recognition beyond voice-driven queries to spoken commands. They're similar in concept to Apple's Voice Control app on the iPhone, but they're more broadly applicable.
Voice Control lets you interact with the iPhone's Contacts app or iPod app using spoken commands.
Voice Actions lets you interact using spoken commands with any app designed to accommodate them, thanks to the Android Intent API, which provides a way for one app to use resources in another app.
At the moment there are 10 Voice Actions supported: send text message; get directions; call contact; view map; note to self; listen to music; call businesses; send e-mail; go to Web site; and search Google.
Android's Intent API makes Voice Actions more useful by sending a voice command like "listen to The Clash" to all compatible music apps -- such as Pandora, Last.fm, Rdio, and mSpot -- on the user's Android phone. This approach makes it more likely that songs by the requested artist will be located and played than a query directed at a single app.
"You can say any music you're looking for and any number of apps will be able to play it for you," explained Google engineer Mike LeBeau.
The updated Chrome-to-Phone extension adds a button to the user's Chrome browser that can send a Web link, a map, YouTube video, or selected phone number or text to the user's Android phone.
Burke describes it as a way "to bridge the gap between the desktop and mobile."
The Chrome-to-Phone extension is open source code, making it likely that there will be versions that allow other browsers like Firefox and Safari to send content to Android phones.
As to whether other phones might be able to use this system, someone would have to implement a cloud messaging system to handle messaging for other mobile platforms. The Android Cloud to Device Messaging (C2DM) service does this for Android devices.
The new version of the Google Search mobile app with Voice Actions and Chrome-to-Phone require an Android device running Froyo (or Android 2.2), the most current version of the Android operating system. They're available in English only at the moment.
Disclosure: Google provided journalists who attended the media event with new Droid 2 phones from Verizon to try out the new apps. The author of this article uses an iPhone 3GS for general day-to-day calling.