VideoCacheView is a simple tool that can create local copies of some of the videos you watch online.
In theory, the program sounds quite straightforward. Just watch the video in your browser, as normal, then allow VideoCacheView to scan your browser cache (IE and Mozilla-based browsers are supported), locate any videos and copy them to another folder.
In practice, it's not always so easy. Timing is important, for instance. If you watch a Flash (FLV) video from a site like YouTube, for instance, then it'll probably be deleted when you close the browser. So if you want to keep a movie then you must run VideoCacheView after it's fully downloaded, but before you shut your browser down.
And if you want to save a video that's been cached by Firefox in the current session, then the story is very different: you must close your Firefox windows before running VideoCacheView, because Firefox maintains its cache in RAM, and only writes it to disc when closing down.
There are some complications, then, but you'll soon get the hang of how everything works, and overall VideoCacheView is still a very useful tool for anyone who regularly watches plenty of online videos.