Motion-activated TimeLapse Video Recorder
Creates a time-lapsed videos from web/ip cameras, JPEG/MJPEG streams as well as from AVI files

Check out a time-lapsed video created from the Stuttgart airport's MJPEG stream - shtutgard_airport.avi

The tool is heavily based on the Andrew Kirillov's open source project AForge and his article Motion Detection Algorithms.

You're welcome to check out the source code of the tool.