"Streaming video websites are such a big part of our lives, it's hard to remember a time when they didn't exist. These websites revolutionized our computer video experience - no longer do we have to download every single video we want to watch - it's all right there!
But the opposite is also true. Sometimes sending a link or embedding a video is not enough, and we need the actual file, or only its soundtrack. And when that happens, the default FLV file format rarely cuts it. Luckily, there are several downloaders-converters out there that make it easy as pie to download videos and convert them into almost every possible format."
Discovery Education is a great resource for educators, with assessment tools, streaming videos, TechBooks (online, interactive "textbooks") and much more..