thanks, will check out what block chain's api does.
Just checked it out, it's more like link shortening.
Even link shortening with custom strings wont suffice, if ownership is based on first-come-first-serve rather than openid/oauth.
eg: anyone can attempt to claim johndoe, but only the real johndoe will be authenticated for johndoe.myopenid.com, thus completing the authentication & claiming it for real.
~B