Apple's Mac OS X comes with a funcalled Photo Booth. It is a tool that allows you to capture photos and apply different filters to it. Whilst the "usefulness" of this application is debatable, I personally find it useful when set to Normal use and taking quick photos for email, etc.
Today, I found a Linux implementation of Apple's Photo Booth and named Cheese. Cheese is "a Photobooth-inspired GNOME application for taking pictures and videos from a webcam."
Whilst it has yet to reach version 1.0 release, this application shows a lot of promise. It even beats Photo Booth by allowing videos to be captured and morphed. Check it out!
[cheese image from cheese website]