Reported to work with FreeBSD 6.2, 7-CURRENT and PC-BSD 1.x
New simple way to install the flash7 plugin:
portinstall linux-flashplugin7 nspluginwrapper nspluginwrapper -i /usr/local/lib/npapi/linux-flashplugin/libflashplayer.so
Note: This did not work, I ended up having to manually download flash 7 and copy the files into the linux-firefox plugin directory.
wget http://watters.ws/rpms/install_flash_player_7_linux.tar.gz tar xzf install_flash_player_7_linux.tar.gz cd install_flash_player_7_linux cp flashplayer.xpt libflashplayer.so /usr/local/lib/linux-firefox/plugins/
After these commands are run you should be able to play flash videos in linux-firefox.