simple download the "not open source" free opera browser
then apt-get install gnash apt-get install gnash-mozilla plugin (or something like that - apt-cache search gnash)
then in opera about:plugin
does it work?
is this necessary too?
$ cd /usr/lib/opera/plugins/ $ sudo ln /usr/lib/gnash/libgnashplugin.so
Unfortunately as of 2009 gnash did not play most flash videos correctly (read youtube, other random websites)... So back to the proprietary version from adobe...