If you’re using opera browser, it doesn’t need any third party apps or plugins for downloading flash/flv video. Basically, Opera keeps all played flv files in its cache folder.. just copy the flv movie from cache to a new location.. that is the only thing you should do, for any project or gaming site , learn it here !

let’s follow the simple instruction below:

step 1: locate the cache folder.
This can done by clicking Help->About Opera. In path section, you can see cache folder. Mine is
C:Documents and SettingsMyiawApplication DataOperaOperaprofilecache4

step 2: increase the disk cache limit.
click Tools->preferences, goto advanced tab and Select history in left list. there is a disk cache combobox which show range from 2MB to 400MB. default value is 20MB. change its value to bigger size..
Due to the usually large filesize of FLV video, you should prepare enough room for keep it. the bigger cache limit size, the bigger amount of cache items can be keep.
uncheck empty on exit will prevent your browser to erase its cache when closing the browser.

step3: browse any video site and watch the flv video..
Go to YouTube.com, PutFile.com, Video Break.com, Google.com, iFilm.com, Myspace or any flv video sites. All flv video you’ve played will be automatically and temporarily saved into cache folder.
just browse at cache folder and find files with *.flv extension.
the filename seems cryptic. It automatically given by Opera..  then, copy the .flv files to your destination folder..

note:make sure you wait for the video to finish downloading or streaming..
you will get only some part of video if you skip/stop the video during its streaming process..