I've found that you can also use the HTTP-EQUIV="expires" CONTENT="0" META tag to prevent caching. I know this isn't directly related to perl, but if you want, check out my pop-up webcam at http://www.angelanthony.com and examine the javascript code in that page. It appends a "?seconds since epoch" to the end of the IMG SRC in yet another attempt to prevent cacheing. ;)