This post is actually not a HOWTO, but a quick tip on how to install Adobe Flash 10 in 64-bit Ubuntu. I’ve tested this in Ubuntu 9.4 with great success using the following commands from a console window.

wget http://queleimporta.com/downloads/flash10_x64_en.sh && sudo chmod +x flash10_x64_en.sh && sudo sh ./flash10_x64_en.sh

Note!
Please read through the script and make sure you know what it does before you run it, to avoid any surprises.

Source: http://queleimporta.com/en/finally-adobe-releases-native-64-bit-flash-10-for-linux/