Every one may have once thought of downloading any video which is played at youtube or dailymotions or any video sites. I have thought of so many times.

This is pretty simple. You don't need a addon or go to another site for it .

For downloading videos and play locally at my system , I am using Mozilla Firefox, and I recommend each and every one to use it . Its the popular opensource browser which is faster than any . Having lots of addons . The only browser that may be supporting HTML 5  . Sorry Opera too is supporting . Looked IE8 and Google Chrome too from my office . No it doesn't  for now , may be in the future . It may not be helpful to users, but great for developers .

So talking about playing a video locally  right . First clear the cache of browser ( Tools->Clear Recent History ) . Firefox 3.5 comes with a great improved techniques . You just need to clear cache . You can clear others too if needed . Its not a big deal if you don't clear cache too . I am clearing the cache to quickly see the file I need .

Play the youtube video or what ever video you need to play . After finished playing the video take a new tab ( Ctrl+t ) , type about:cache in the address bar . I have just kept a screenshot .

Copy the cache directory and paste in your favourite explorer . I am using Nautilous , windows guys paste in the explorer . Now you can see lots of files. Arrange them according to file size . Go and play the videos using vlc ( Video Lan Controller ), another opensource player . One of my friend and collegue was behind this post. His name is M S Sujith .

You don't need any addon . Have it . Remember to move from cache if you need it permenantly . Thanks