BrowserID lets you use any number of email addresses and choose which one to use...

mbrubeck on July 12, 2012 | parent | context | favorite | on: Introducing Mozilla Persona, An Identity System fo...

BrowserID lets you use any number of email addresses and choose which one to use for a given site (though I think the current UI might get a bit cumbersome if you have dozens attached to one Persona account).