Breakout is now available in the Chrome Web StoreSat, Jun 18, 2011
UPDATE: This article is now out of date, I transferred ownership of the chrome app store version of breakout over to a 3rd party and its no longer available from me.
It’s surprisingly easy to use the Chrome Web Store, pretty much all you need to do is summarised right in the online help
Interestingly, perhaps mercifully, the soundmanager2 library doesn’t seem to work well when hosted in a packaged application within the chrome store. So there are no sounds available in this version, but everything else should work.