Can’t find the Site Directory template when creating a site in SharePoint 2007?

Neither could I.  The problem was that I didn’t have the “Office SharePoint Server Enterprise Site Features” site feature and “Office SharePoint Server Enterprise Site Collection Feature” site collection features activated.  Once I activated them, I got the Site Directory as an option as expected.

(Note: if you still can’t see the template after activating those features, try navigating to http://<your_site_root>>/_Layouts/AreaTemplateSettings.aspx and adding the Site Directory template to the available list, then try again.)