Recently in the Pebble Community on Google + a Kickstarter was mentioned which would give you the capability to do a voice search from your Pebble. I believe it was called OK Pebble.
You can do this already with an app called App Launcher. There are three voice activation apps that currently show up in App Launcher. The one I settled on was Google App.
I currently have App Launcher set up for the top quick launch. After pushing the botton either selecting g or shaking my wrist activates voice activation on my phone.
In addition to Google App you can open any of the apps on your phone with your Pebble. This could be Gmail, Calendar, Camera or any other app you choose.