As stated by Joelo in its post :
The Security & Compliance Solution Accelerator team has put together some guidance and a solution to quickly deploy an extranet solution based on WSS or SharePoint Server 2007.
The setup and configuration guidance is based on forms authentication with ADAM for external accounts to be deployed with WSS or MOSS 2007. The beta bits include 1) a self service and approval workflow process for site collection creation, 2) a self service and approval workflow process for partner account creation and 3) a management interface for approving and managing accounts and site collection creation approval or removal.
Have more details from the dev team here : http://blogs.msdn.com/sharepoint/archive/2008/01/03/new-beta-extranet-collaboration-toolkit.aspx