Adobe Flash 10 Astro on Ubuntu 64 bit

http://ubuntuforums.org/showthread.php?t=1081964

1) Remove previous existing versions of flash player

apt-get remove --purge flashplugin-nonfree gnash gnash-common mozilla-plugin-gnash
apt-get remove --purge swfdec-mozilla libflashsupport nspluginwrapper iceape-flashplugin
apt-get remove --purge iceweasel-flashplugin mozilla-flashplugin firefox-flashplugin
apt-get remove --purge xulrunner-flashplugin midbrowser-flashplugin xulrunner-addons-flashplugin
rm -f /usr/lib/mozilla/plugins/npwrapper.libflashplayer.so
rm -f /usr/lib/iceweasel/plugins/npwrapper.libflashplayer.so
rm -f /usr/lib/firefox/plugins/npwrapper.libflashplayer.so
rm -f /var/lib/flashplugin-nonfree/npwrapper.libflashplayer.so
rm -f ~/.mozilla/plugins/npwrapper.libflashplayer.so
rm -f /usr/lib/firefox-addons/plugins/npwrapper.libflashplayer.so
rm -f ~/.mozilla/plugins/*flash*
rm -f /usr/lib/firefox/plugins/*flash*
rm -f /usr/lib/firefox-addons/plugins/*flash*
rm -f /usr/lib/mozilla/plugins/*flash*

2) Download the 64 bit Flash Plugin (Alpha) from its website

wget http://download.macromedia.com/pub/labs/flashplayer10/libflashplayer-10.0.42.34.linux-x86_64.so.tar.gz

http://labs.adobe.com/downloads/flashplayer10.html

4) copy it in its folder

cp libflashplayer.so /usr/lib/mozilla/plugins

5) Restart Firefox, open youtube and be sure the plugin works

If you're using the Opera browser:

Do this only if, after having done point 4 and 5, you can't experience flash in Opera

4) Maybe Opera isn't searching into the Mozilla Plugins folder, then let's put the Flash plugin in its folder. The steps are the same as above, the only difference is step 4

cp libflashplayer.so /usr/lib/opera/plugins

5) Reboot Opera