Demand for OpenID providers to claim identity, apart from consuming

Hi,

this is a great way to pool demand for OpenID consumption (so you can login with your existing openID to a website).

Another issue is that sometimes I explicitly want to claim the identity I've built up somewhere (on Site X). If that particular site X were an openID provider, then I could prove to yet another site Y that I am this or that person by logging in to Y with my X OpenID account.

Typical example: there's a flurry of web communities, forums and blogs on Second Life. It would be great to actually prove there that I really am e.g. http://secondlife.com/avatar/MySecond...

So there should be a way to demand that a site becomes an openID provider as well...