Double-tapping with two fingers zooms Safari to that element similar to MobileSafari…
Quickly enter (and exit) “jiggly app mode” in Lion’s LaunchPad One of…

Twitter for Mac and the three-finger swipe

Use a three-finger swipe over a tweet in Twitter 2 for Mac…
If you have multiple keyboards (languages) enabled on iOS 4 under Settings…

iChat Video Conference gestures

When in a video chat you can use the zoom in gesture…
Hootsuite, a Twitter client for businesses and other groups, lets you share…

WeatherBug Elite: Tap anywhere for a quick weather report

In WeatherBug Elite, you can tap-and-hold anywhere on the map to drop…