The smf community may want to consider building a stand alone application that integrates the smf user base and login with Joomla! 1.5+ upon initiation by the webmaster or server administrator.
It could check for new joomla users every so often, and then create a new user account for smf; or vice versa. I know that this type of dual login application would be much appreciated by many of us. The current scripts and modules do not work properly at all.
TMax.
This belongs in Portals, Bridges and Integrations. Also, there have been many questions like yours before, I'd recommend searching for them.
Moving this.