Update v1.1 : now minification works properly !
The plugin : https://dl.dropbox.com/u/1412774/FaceDetectDemo2/pode_facedetect.1.1.zip
Here's a new behavior, allowing you to detect a face in the Sprite it's attached to. You can get the (X,Y) of the found face, its width and height, the confidence (only the first found face is reported).
<img src="https://dl.dropbox.com/u/1412774/FaceDetectDemo/demo1.png" border="0">
As you can see in the screenshot, there's also the possibility to retrieve a cropped version of the found face (you can give the margin you want to add around the original found face, since the bounding box can be a bit "tight"). The cropped image is given as a base64 string that you can load in a regular Sprite.
<img src="https://dl.dropbox.com/u/1412774/FaceDetectDemo/demo2.png" border="0">
The whole thing was made using the helpful jQuery FaceDetection plugin : http://facedetection.jaysalvat.com/
The demo : https://dl.dropbox.com/u/1412774/FaceDetectDemo/index.html
The plugin : https://dl.dropbox.com/u/1412774/FaceDetectDemo/pode_facedetect.1.0.zip
The .capx : https://dl.dropbox.com/u/1412774/FaceDetectDemo/FaceDetectDemo.capx
I'm planning to add several face detection in the same image in a future release.