ActionBarSherlock is an Android support library designed to allow you to use the ActionBar which was introduced in Android 3.0 Honeycomb with older devices, back to Android 2.1 Eclair. This allows your applications to have a modern looking interface, even on older devices whose API does not support the new features.
To get started using ActionBarSherlock in Eclipse follow these steps.
Visit http://actionbarsherlock.com to download and extract the latest version to a development directory. You will be including this directory as a library in your app.
In Eclipse choose File -> New -> Other and select “Android Project from Existing Code”. Select the “actionbarsherlock” folder withing the directory of the zip file you just extracted. Eclipse should detect the project and import it into your workspace.
Create a New Application
If you are going to add the ActionBar to an existing application skip this step.
Create a new Android application. I recommend the lowest minimum SDK you can use for your application (no lower that API 7). And set the target SDK to the highest version you can support (ideally the newest Android version). Finish the rest of the new application wizard so that Eclipse shows you your newly created application.