Lion - Removing icons from LaunchPad
By default, Launchpad shows everything in your Applications folder including your home ~/Applications folder. This can get too cluttery sometimes so here is how to remove them without deleting them from the Application folders.
Directions:
Step 1 - Go to the Dock and open Launchpad.

Step 2 - Click and hold on an icon until you see all icons wiggle.
Step 3 - Click the "x" button in the upper-left corner of the app icon you want to delete. Note: If you do not see an "x" button, either the app is not from the Mac App Store or you are logged in as a standard user.

Step 4 - Click "Delete" in the confirmation dialog to delete the app.

Tip: If you want to reinstall a deleted app, open Mac App Store, click the Purchases icon, then click on the "Install" button for the app.