In a story, The Best Video Download Tools on our sister blog NewTeeVee, Liz Gannes has identified a very useful extension for (almost) everybody's favorite open source browser: Firefox. Liz's pick is optimized for downloading and saving video segments for the web--for those items you don't just want to stream and forget about. I've taken her extension for a spin in Firefox, and it looks very good for anyone doing a fair amount of web video viewing. It comes with a helpful set of tutorials, too.
Video DownloadHelper is optimized to help you quickly download and save video from the web, but it also deftly handles audio files and picture galleries. This Firefox extension stays in your toolbar as an icon and makes itself available when you get to a page that has video.
Video DownloadHelper is optimized to let you download batches of videos at once. If you're downloading quite a few video files at once, a small download queue counter shows up atop your browser. This is useful for figuring out how long it will take to snag video files, which are typically very large. In Liz's post, she identified this page which is loaded with video tutorials on using Video DownloadHelper.
For more useful extensions for Firefox, see our previous post, and the 25 reader comments there with lots of other favorite extension nominations. Also see our post on essential open source video and animation tools.