How Do I Use Launchpad In OS X Lion?
To open Launchpad in OS X Lion, simply pinch with three fingers and your thumb. You will immediately see pages of applications similiar to the home screen on an iPad or iPhone. Swipe to the left or right with two fingers to navigate between pages of applications.
You can move apps into different positions by dragging and dropping them and you can group apps into folders by dragging an app on top of another to create a folder. At any point you can delete an app you purchased from the Mac App Store by holding down on the app and clicking the Delete button. You can always recover it by re-downloading from the Purchases list in the Mac App Store.