Douglas Stanley from abstractmachine has announced the release of his OpenCV package for the Processing software.
The OpenCV package contains, amongst other things, face detection, image treatment and countour tracking.

The package is open source and free as is Processing so if you're interested in doing any kind of visual based work Processing is a good place to start and this OpenCV package would be a good addition to your toolkit.
The above link also takes you to a number of example projects that have used the OpenCV package.