[OpenID] Proving your OpenID to foreign domain

[Yonas .]

Hi,

I'm looking for a way that a YouTube/MySpace/etc user can prove to me
that they own that account.

OpenID will give me a URL that represents that user, but not contain
the actual username. Is this being worked on or looked into?

I understand why the URL is not required to be the username, but I
believe OpenID should provide a simple way of saying, "You requested
proof of ownership for 'john.doe at youtube.com', and yes, the user is
the owner".

Cheers,
Yonas