clipped from: www.downloadhelper.net   
DownloadHelper is a way to discover many sites showing Web videos from all around the world. They are here !
DownloadHelper is also a free Firefox extension for downloading videos and images from many sites with minimum effort. Install the extension !

Using DownloadHelper, you can easily save videos from most of the popular video sites. (Check here for lists of supported sites).

It is also possible to capture all the images from a galery in a single operation.