its called open id

OpenID has not achieved mass adoption.. being able to use my Facebook, Plurk, MXit or GMail, etc. to sign up would be better..

it's up to the web service to make those option available to me.. they must tap into the APIs available to them...

true, though i think a centralized identity solution would be best, linked to your social graph, there are discussions around that in DP

does the average user really know or care about OpenID or any centralised ID solution? They just want it to work...

we have to minimize the education required to maximize adoption...