Loading authentication subkey into gpg-agent?

[Lars Kellogg-Stedman]

Hello all,

Is there a way -- not involving third-party tools -- to load an
authentication capable subkey stored in my GPG keyring into a running
GPG agent?  I can use 'monkeysphere subkey-to-ssh-agent' (and I am, and
it works fine), but given that both sides of this equation are from the
same source, I was wondering if there is a more integrated solution
these days.

Thanks,

-- 
Lars Kellogg-Stedman <lars at oddbit.com>