Thanks for the suggestions.
Keepvid.com looks good, but it won't help for this application. This is a website where I click on an embedded "Watch this Video" link in a page, and a JWPlayer popup comes up and plays the flash video. The URL doesn't change, so it won't work in Keepvid.
I'll have a look at Firefox add-ons like Download Them All (I primarily use Firefox on Mac and Windows). Do you know if it will grab a popup flash app like JWPlayer?
Where Leviathan can, it will. The state, by its nature, always prefers security to liberty. Lately, technology has offered it means it can't resist, means of mass surveillance that Orwell would have been amazed by. The process is inexorable – unless it's resisted. Obviously, we need protection from terrorism, but not at any cost. - Ian McEwen