PicBlock   
http://www.cinchworks.com

Protect yourself and others from accidental or intentional exposure to pornographic images on the Internet. PicBlock is a revolutionary tool that blocks pornographic images from displaying in your e-mail client or web browser. Unlike traditional porn blocking tools that rely on keyword filters and constantly outdated blacklists, PicBlock blocks porn by detecting the amount of flesh tones in images. Features include: -Works in any web browser, -Works in any e-mail program, -Is a cinch to install, setup and operate, -Lets you set permissions for what users can and cannot do, -Lets authorized users unblock images incorrectly blocked, -Maintains a list of safe sites as a result of an unblock action, -Maintains a protected log of all block/unblock activity, -Is tamper resistent, even for computer savvy individuals, -Best of all, it's absolutely FREE!