Here are some tools I have found useful in capturing video, specifically from the web.
Download Helper (Extension for Firefox
This is by far the best tool I have found for capturing FLV and MP4 videos from the web. All you have to do is visit the web page with the video you want to grab. Once the page is done loading (and the video has started to stream) the extension icon will activate indicating that it has found a video to download. Click on the icon and select the file you want to download. This works especially well with YouTube. When you click the icon it will let you select from what ever size you want to download whether it be 480p, 720p, 1080, etc.
CamStudio is a open source project used for capturing video directly from your screen. This means if you see it on your screen you will capture it. The software has a few settings for video and audio quality. The Biggest issue I had with this CamStudio was that to get the audio to capture as well you need to use the ‘Stereo Mixer’ audio input (essentially loops your current audio output back to your PC). When doing this I was unable to eliminate a minor feedback I was getting, I think probably from the poor quality audio hardware I have in my work computer.
AviScreen is very similar to CamStudio. Both are good tools for creating screencasts.
It is also worth pointing out that neither CamStudio or AviScreen are incredibly user friendly and are definitely lacking in UI quality, but hey what else can you expect from a piece of software that probably doesn’t make any money for it’s developer.