Ok, problem solved. I got a Firefox add-on called "Flash and Video Download v. 1.2.1", and it works fine. I'm saving to .flv files and using VLC to play.
Thirty years from now there will be a huge amount of oil - and no buyers. Oil will be left in the ground. The Stone Age came to an end, not because we had a lack of stones, and the oil age will come to an end not because we have a lack of oil. - Saudi Oil Minister Sheik Yamani, in 2000