I'm one of the lead developers on this project. The voice recognition program that OMG! Ubuntu! showed is not being developed by Canonical. We currently do not have a PPA but you can find the project on GitHub.
We are also occasionally on IRC #speechRecognition
In order to install Linux Speech Recognition go to the project's GitHub page. Download the ZIP file and extract it.
Then install some dependencies:
sudo apt-get install sox python-argparse libsox-fmt-mp3 mutt xvkbd xautomation
Open the extracted folder (Palaver-master) in the terminal and execute the setup:
Now it is just to assign a hotkey to enable recording, in order to do that go to System Settings... > Keyboard > Shortcuts > Custom Shortcuts click the Plus Button to add a shortcut, name it Voice Recognition and set the command to:
Click apply, click over the shortcut and then assign a hotkey to activate Voice Recognition.