[alphadog]

Interestingly enough, I notice it on http://www.wunderground.com/ homepage using Chrome.

Not exactly sure how they're using it?

[ch0wn]

All you need to do is add the x-webkit-speech attribute to the desired input element:

<input name=query x-webkit-speech>

[mildweed]

http://www.w3.org/2005/Incubator/htmlspeech/2010/10/google-a...

I, for one, can't wait till Android and iOS implement this.

[superchink]

I managed to dig up this blog post (http://mikepultz.com/2011/03/accessing-google-speech-api-chr...) that seems to explain how to use it for your own purposes.