As reported by OSNews, Adobe just released an Alpha version of 64-bit Flash plugin for Linux.
It still doesn’t support transparent backgrounds, but at least it doesn’t crash every five minutes like nspluginwrapper.
Here’s how to install it on Ubuntu:
Download the new flash plugin from here. Then, in a terminal type these:
tar -xzf libflashplayer-10.0.d20.7.linux-x86_64.so.tar.gz
sudo apt-get purge flashplugin-nonfree nspluginwrapper
mv libflashplayer.so ~/.mozilla/plugins