Mozilla has tons of stuff in production running Persona, so we're totally dogfooding with Bugzilla, Mozpad, MDN, Add-ons Builder, Firefox Affiliates, Firefox Flicks, Mozilla Marketplace, and Mozillians.

Voo.st, OpenPhoto.me, Crossword.TheTimes.co.uk, 5apps.com, Haskellers.com, etc. We're also working to get Persona working with some larger sites, but most of those are waiting to go live until after we formally announce API stability next month.

I don't think there's an official list, here's two:

* http://noteplz.com/

* http://textchannels.com