A quick and easy way to download a video on YouTube or Vimeo, is using KeepVid.
Copy the link from YouTube, paste it in the field on KeepVid and press download. You need to have Java installed, which you can download here.
You’ll get a list looking something like this:
The number at the end is the video resolution height. For example 720p stands for a video resolution of 1280×720. The ‘p’ stands for progressive, and is generally better than ‘i’. The higher the number the better the quality.
Alternatively you can make a bookmark linking this code:
When watching a video if you click the bookmark, you’ll be sent directly to the download page.