It allows you to easily search almost any information directly from Unity Dash
The Ubuntu Answers Lens is an Unity Lens that allows users to easily and quickly find answers to common questions directly from Unity Dash.Users will be able to right click an answer in order to view detailed information about what they searched for. The Lens uses the automatton.org API for queries, which gathers information from popular websites like Wikipedia, Yahoo! Answers, etc.
To install the Unity Answers Lens plugin in your Ubuntu operating system, open a terminal window (hit the CTRL+ALT+T key combination) and paste the following commands (one by one, hitting Enter after each one):
sudo add-apt-repository ppa:scopes-packagers/ppa
sudo apt-get update && sudo apt-get -y install unity-lens-answers
You will need to restart your session after the installation. This Lens is available only for the Ubuntu 12.10 (Quantal Quetzal) and Ubuntu 13.04 (Raring Ringtail) operating systems.