Though you can now enable Flash on Google Chrome for Mac, the Linux still doesn't have support. However, if you're willing to run Chromium instead of the official Google build, you're in luck.

Using a current version of Chromium from Launchpad, adding Flash to the speedy browser is a breeze. H3g3m0n posted a tutorial on how to enable Flash in Chromium but that post is outdated and some more tweaking needs to be done for this to work: