IN2AR is an ActionScript3 and Adobe Native Extension Library that allows you to detect images and estimate their pose using standard webcams/cameras or mobile cameras.
The pose information can be used to place 3D objects and/or videos onto the image and create wonderfull Augmented Reality applications, or to create unique games that can be controlled by movements of your image or phone. This application shows this technology in action. Print out http://www.in2ar.com/demo/marker.jpg and look to this image with your phone to see the 3D model appear.