Just found a firefox plugin that can make living without flash a bit easier. It's called FlashVideoReplacer. It only works for flash videos of course, no games or anything else. I have already set youtube to play html5 videos, but for the few times that only the flash version is available, this works. Until now, if a video was not available in html5, I just wasn't viewing it. It introduces a small glitch when starting webm videos, but they play fine in the end. It also supports other sites, like vimeo, metacafe and a few more. Works fine as far as I've seen.
You need mplayer for this and probably also mplayerplug-in. I've only tried it with the mplayer2 package+mplayerplug-in we have in the 13.37 repositories, should work with the old MPlayer package too I guess. Maybe it could work with the parole web plugin, but I didn't try it.