VideoDownloader

The VideoDownloader Firefox extension is an extremely useful tool. You get an icon in the bottom right, which will allow you to download every video on the page you are viewing. It works with most major video communities: Youtube, Google Video, iFilm, Metacafe, Daily Motion, Myspace etc. The file format is .flv, which I don't know, but it plays in Media Player Classic, which is all the video player you need, anyway.