But this is actually pretty cool. It may seem prudish, but if you have antiporn rules you need to enforce on any sort of Web app that allows uploads, this could be helpful. The author, Patrick Wied, suggests it could be used in client-side proxies to ensure child-safe surfing.
Wied's also written an article on the first improvements and next steps for the program here.
You can download the sourcecode from Github.
What do you think? Cooler than this HTML5-based face detector?