From David Chartier at Finer Things Mac:

Quickly enter (and exit) “jiggly app mode” in Lion’s LaunchPad One of Lion’s new features is called LaunchPad, and it is essentially the Springboard home screen from iOS, adapted for organizing and launching apps on the Mac. Similar to iOS, you can click-hold on any app icon to enter app organization mode, also non-technically known as “jiggly mode”. But to get in and out of this mode even more quickly, you can simply hold the Option key. Icons will jiggle while the key is depressed, so you can move them between pages, drag them onto each other to create folders, and delete them. Let go of Option and your changes are saved. Someone with better video editing skills than I needs to cut together a short 30 second music video of the icons dancing to latin music by hitting the option key to time the icons' 'dancing' to the music. Free idea. You're welcome.