Have you ever tried your hands for developing a lens for Unity ? Here is a nice tutorial from canonical on how you can start writing your own custom lenses for Ubuntu 12.04.

Lenses are a central part of the Unity desktop, and anybody who’s used it will be familiar with the default Application and File lenses, maybe even the Music lens.

But there’s so much more to this technology than you might think.

The Unity Dash provides a lightweight, instant and easy means to browse and retrieve interesting content. Through the use of lenses, it enables the user to search for information both locally and remotely.

In this tutorial  you’ll learn how to easily write a lens to comfortably search the Wikipedia right from your desktop. And will demonstrate how you can easily create lens for the Unity dash to enrich the Ubuntu user experience and provide the ability to search on the wikipedia right from the desktop.

For additional information you can also refer to the Unity lenses documentation.