As an experiment, several years ago I released a few "fun" iPhone apps that leveraged OpenCV to do face detection and image replacement using the iPhone camera. I did dozens of successful tests before launch, and the apps have collectively been downloaded hundreds of thousands of times. I'd say overall effectiveness in the wild is pretty high, but it depends on the filter used. If anyone is interested I can send a link, but don't want to spam this audience with it.
What was you overall success of the apps? I've been trying to create some for the Droid market, then branching into iOS. Is it the kind of thing that can take over a full time job, or just extra pocket cash?
