Thanks, everyone, for the great suggestions! Just you you all know, I am
using Firefox and not Abrowser.
@oralfloss: I can confirm that Gnash is enabled and the latest version.
@Cyberhawk: Unplug works like a charm. Greasemonkey with Linterna Mágica,
though, is useless. It doesn't seem to do anything.
@Mzee: I already have LightSpark installed. It does not appear to work in
Firefox and I really ought to remove it.
@ADFENO: On Vimeo, in particular, it's a no-win situation. If I enable Gnash
I get a still image that does nothing; if I disable it I get an error message
"This video can't be played with your current setup. Please switch to a
browser that provides native H.264 support or install Adobe Flash Player."
