a few years back i heard about http://code.google.com/p/surveillancesaver/ and loved it. so i patched a couple of things on it that i didn’t like, and in the process of playing with it decided to make an os x dashboard widget.
both the saver and the widget have the same problem in that the url list for the cameras is hardcoded, and while i keep meaning to make a feed for them to use, i never get around to it.
still, this thing was pretty quick, easy, and fun to make.