A script I found to install Flash on Ubuntu 9.10 64bits

#!/bin/bash
# Script created by
# Romeo-Adrian Cioaba romeo.cioaba@spotonearth.com
# Super minor updates by jason.melton[at]gmail[dot]com
# Updates by Alejandro Cuervo 3[at]cuervo[dot]net
# more very minor updates by damien[at]groovey[dot]com
# Released under GPL

echo "Closing Firefox"
sudo killall -9 firefox

echo "Downloading and instaling Getlibs for required libraries"
wget http://www.boundlesssupremacy.com/Cappy/getlibs/getlibs-all.deb
sudo dpkg -i getlibs-all.deb

echo "Removing previous installs of flash:"
sudo apt-get remove -y --purge flashplugin-nonfree gnash gnash-common mozilla-plugin-gnash swfdec-mozilla libflashsupport nspluginwrapper
sudo rm -f /usr/lib/mozilla/plugins/*flash*
sudo rm -f ~/.mozilla/plugins/*flash*
sudo rm -f /usr/lib/firefox/plugins/*flash*
sudo rm -f /usr/lib/firefox-addons/plugins/*flash*
sudo rm -rfd /usr/lib/nspluginwrapper

echo "Installing ia32-libs and nspluginwrapper"
sudo apt-get install ia32-libs nspluginwrapper

echo "Getting libs"
sudo getlibs -p libcurl3
sudo getlibs -p libnss3-1d
sudo getlibs -p libnspr4-0d

echo "Installing Flash Player 10"
cd ~
wget http://fpdownload.macromedia.com/get/flashplayer/current/install_flash_player_10_linux.tar.gz
tar zxvf install_flash_player_10_linux.tar.gz
sudo mv libflashplayer.so /usr/lib/mozilla/plugins/
sudo nspluginwrapper -i /usr/lib/mozilla/plugins/libflashplayer.so

echo "Linking the libraries so that firefox can see them."
sudo ln -sf /usr/lib/nspluginwrapper/plugins/npwrapper.libflashplayer.so /usr/lib/mozilla/plugins/
sudo ln -sf /usr/lib/nspluginwrapper/plugins/npwrapper.libflashplayer.so /usr/lib/firefox-addons/plugins/

echo "Done :-)"
echo "You may re-start Firefox now"