I have a pop-up that displays a local webcam shot. I use: <meta http-equiv="refresh" content="10"> to refresh the window, thus pulling in the new shot that's redundantly ftp'd every 10 seconds, overwriting the old shot. Works well and I never really needed anything more sophisticated as far as scripting.
However, recently I have been seeing 2-3k in daily hits for this little window (normal is a couple hundred.) The webcam window has no toolbar, however I believe a user(s) may be saving it or just letting it refresh in the background indefinitely.