The Firefox cache is its version of Internet Explorer’s Temporary Internet Files. It’s a local storage of files so that Firefox loads some things locally speeding up the loading process and saving both you and the site some bandwidth. Firefox offers access to it by going to a “hidden page” called about:cache.
Last time, I featured a front-end GUI for about:config . So here’s one just for the cache. CacheViewer serves as your front-end GUI while navigating through the information stored in your cache. It allows searching and sorting through both Firefox’s memory and disk caches.
There are some joys in scavenging through your cache. If you want to save media files like photos and Flash SWF files, chances are, they also get stored in the disk cache. Once you find them, you can even make copies of these files and store them in another local location. CacheViewer even has an image preview to boot.