"A new and free iOS app called Action Movie FX lets users create Hollywood special effects on top of a video by using their iPhone's camera."
How cool is that? And very simple to use from what I've read, all you do is record a target and then the application does all the hard work. Car Smash and Missile Attack are free with the app and you can purchase other ones for $0.99 USD from within the app.
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iPhone 4, 1.6 GHz Core 2 Duo MacBook Air, Apple TV, 2.66GHz Intel C2D Mac Mini, 1TB TC, Airport Extreme,several iPods and an iPad, 32GB Wi-Fi version. Follow me on Twitter.