If u r after a Youtube video, perhaps you'd probably go after a flash video download plugin for your browser.

But guess what, i dont think that would be required, if you know where your temporary files of firefox are. This way you can get all most what ever you want on the page... which would include photo's as well. This method of obtaining what you want is convinient according to me... especially when it comes to getting your flash videos.

This is what, you have basically have to do.

Figure out where mozilla is installed. It will usually be in the following directory /home/<usr_name>/.mozilla, where <usr_name> should be your username. To directly get to your directory click on the desktop and press Ctrl+L together. And a new window saying 'Open Location' will open, in there by dafault it will have /home/<usr_name>, all u need to do is replace it with /home/<usr_name>/.mozilla/firefox/<some-string>/Cache

similarly if you are looking for other temp files, go to your home folder and press Ctrl+H to view your hiden Files... just browse for the cache folder... and u have your temporary folder present... as simple as that.

This will definitely work on Ubuntu.

This is for files like flash movies, images embedded in the webpages. For files on which you click Open on the Download Manager, the files are stored in /tmp/<original-file-name>