The same user who spotted the supersized Google sitelinks is now saying he is seeing a new feature being tested by Google for voice search on Google.com.
The feature seems to detect if you have a microphone enabled on your computer and if your browser support it. If it does, it adds a "Speak Now" widget to the search bar so you can use Google's voice search feature instead of your keyboard.
He posted a screen shot of the "Speak Now" feature on WebmasterWorld. It looks like this:

The user promises to not be using the Google Chrome extension Voice Search which seems to be doing the same thing. Do I trust him? I think so. He said, "Not using any extensions this just popped up tonight. From what I understand this was only available with mobile devices in the past."
Another user on Twitter said he spotted this as well. @NatoriousFAT said: "I just discovered the microphone button on Google. I'm never typing a search again."
Anyway, it would not surprise me to see this in action on Google as a test.
Forum discussion at WebmasterWorld.

Comments:
butlerpcnet
05/02/2011 08:36 pm
guess it makes sense since they already have millions of users on Android using their voice input services
Josh
05/03/2011 02:32 pm
I was thinking about this morning...if it was the only option available, how much would it cut down on personal searches at work?
Nihal Nambiar
05/04/2011 10:59 am
This feature is available to me too ... check out attached snapshots! Moreover I found that it is very accurate for most spoken queries!!! Good stuff Google
mikycomputers
06/20/2011 08:20 pm
Does it work for you? Tell you the truth, I don't have problem to type stuff on kb. This is too early, most of use is keyboard not speech.
Bkjjkjk
06/22/2011 10:05 pm
Visit google.com/experiments or search for google experiments and opt in
Darrion Hall
07/22/2011 12:57 am
i gotta say, i loveeeee it, keep up tha good work google
Ethan
08/07/2011 01:59 am
ya its cool
Michelle Obama
09/05/2011 02:29 am
:P
Miss Sharlet
05/23/2012 04:44 am
the piano keyboard was sweet-very nice surprise to be able to play back--and the speak instead of typing is amazing