If you have trouble getting flash working with Chrome on Ubuntu 64 bit, these steps worked for me:
First you need the 64 bit flash player from Adobe. They have it available (called "Adobe flash player square" at the time of this writing. Who knows what they will call it in a year. Just get the 64 bit Linux tar.gz file) from their downloads site.
Next, extract the contents of the tarball you just downloaded. It contains libflashplayer.so, which you will want to place in your chromium-browser's plugins directory. Mine was in /usr/lib/chromium-browser/plugins. If your chromium is not there, run "locate chromium-browser" and look for a plugins directory.
After moving the plugin into Chrome's plugins directory, restart your browser. That should do it.
(Done on Ubuntu 10.04 and Chromium "11.0.696.65 (84435) ")
