DownloadHelper is a FireFox extension which will do just that. What it does is download the video through your browser(Firefox) and saves it as a .flv(flash) file. Which you can view through a flash player or convert it into another format using a separate program. I find this feature addicting and easy to use. Here is a quick overview of how to use it:
After downloading and installing the program from DownloadHelper.net you open Firefox and look for the DownloadHelper icom in your toolbar(up top). Go to a web site such as YouTube and go surfing away.
Hover over the colored icon and choose the right side of the icon with the small arrow and click on that. A small pop out window will appear with the video title(or titles) that appear on the page.
When you click on the video title another window will appear asking you where you'd like to save your video. Click on Save and your download will proceed.
A quick observation is that I've gotten a couple of partial downloads. I think this is because I surfed away from the page before it was finished. Though I'm not positive about this to be sure I usually leave that window open and if you'd like to continue surfing just open another window or Tab in your browser. Like I said this can be addicting and is probably my most used Firefox extension. Next I'll show you how to view your videos in part 2. Thanks for coming by.