getting video off net sources?

I don't know that there's a *generic* one in the sense of Audio Hijack. There are things like Podtube that record specific kinds of sources, though (e.g. flash) and then a lot of other formats allow you to save them from within the plugin.

Podtube

 

I used PodTube until I found this PodTube only works for about half the time for me. It would sometimes be stuck at "Encoding" forever.

 

Zamzar.com doesn't even require a program... it was originally for converting files without a program, but it can also be used for Youtube videos.

http://www.zamzar.com/tools/

IF you drag the browser button to your favorites toolbar, when you're on a youtube site you can just click it and it will take you to their site where you enter in the file type you want it in and your email address. It will convert the file and email you a link to download it. This works for all different formats of videos, and you can save them in all different types. You can also use this site to upload files to be converted into other file types. All without having to download a bunch of programs. Of course since it uploads and downloads the file would need to be reasonably small or you have to have a lot of patience.