Workaround for watching .flv videos on slow computers

I have a 1.6GHz processor, a GeForce 440 MX, and 376MB of RAM. But it seems I have to upgrade to a GeForce 8-series or something to play friggin' flv video in Linux. Until I can do that, I think I'll have to use this workaround:

• Let the video buffer completely.
• Close the window so that it stops sucking 100% CPU
• Go to the .mozilla/firefox//Cache directory
• $ ls -lhS
• The entries on the top are the largest, one of them will be the video. Try running them with mplayer.
• Copy and rename if the video is worth saving on disk.

This works with youtube, but I think it should work with any website that allows videos to be buffered.