blog.fpmurphy.com explains how to do it for Firefox.

For Google chrome, assuming you have installed the latest stable version (google-chrome-stable-8.0.xxx.yyy) of Google Chrome, create the plugins directory inside /opt/google/chrome/plugins. Copy/Symlink the libflashplayer.so and restart google chrome with

google-chrome –enable-plugins

In about:plugins, you must be able to see the latest version of flash (square) ( r10.2.x )