You can use this to implement a surveillance solution with a webcam.
motion is good in motion detection.
Pretty lightweight , yet flexible and feature-rich daemon.
http://www.lavrsen.dk/foswiki/bin/view/Motion/WebHome

Note that the version build against straight openSUSE repositories
does not contain support for video encoding -- you need to rpmbuild
the .src.rpm yourself on a system that has ffmpeg installed to get
those capabilities.