Camera Monitor is a little tray system icon that notifies you when your Webcam is on or off.
It is designed for the GNOME desktop, but will work as well on KDE and XFCE. Camera Monitor is released under the terms of the GNU General Public License (http://www.gnu.org/licenses/gpl.txt)
Launch cameramonitor on command line:
cameramonitorOr from GNOME menu: Applications -> Sound and video -> Camera Monitor
Change preferences on command line:
cameramonitor -pOr from GNOME menu: Preferences -> Camera Monitor