Here is how I have a (mostly[1]) working flash in a 64bit browser:

  1. take the rpm's (both) from ndpluginwrapper home page
  2. alien -d them
  3. dpkg -i nspluginwrapper*.deb
  4. apt-get install linux32 ia32-libs-gtk gsfonts-x11
  5. get flashplugin-nonfree_9.0.21.78.3_i386.deb from an i386 mirror
  6. dpkg -i --force-architecture flashplugin-nonfree_9.0.21.78.3_i386.deb
  7. dpkg -L flashplugin-nonfree|grep so | xargs rm -f
    yes it caused me some problems, so I'm not sure it's needed but it won't hurt

and then as a user (system-wide installation of the flash plugin does not work for me at all but quite well as a user) :

  1. mkdir -p ~/.mozilla/plugins
  2. nspluginwrapper -i /usr/lib/flashplugin-nonfree/libflashplayer.so
  3. and then go to about:plugins, you should see flash appear here.

It works for many flashes here, except, as said, for the parts that link to an external content.

I've read in many places that the flashplayer 7.0 works better than the 9 one, but the method should globally not vary a lot.

Note: to make it work for konqueror I had to restrict the places where it looks for plugins to /usr/lib/firefox/plugins + /my/home/.mozilla/plugins, and as said, it crashes quite often and randomly.

Notes

[1] Actually, links to external pages from flash do not work it seems, and sometimes it crashes, even very often in konqueror, a bit less in firefox