Configuring External Access to SharePoint?

We’ve actually got a SharePoint Intranet up-and-running for both internal and external users. However, our external users have to enter domain\username when logging in from the Web. I’d like to be able for them to just enter ONLY the username (less confusing that way). I’m reading that I need to enable forms-based authentication with active directory integration for external access but leave integrated authentication for my internal users. Has anyone done this? If so, are you familiar with the steps involved? Thanks!