I noticed in the orchard file structure for App_Data, there was a folder called Sites, and within that, a folder called Default, which therin contained the .sdf and such for an orchard instance.

I looked around and could not find an answer - is it possible to store multiple sites in here, and name them and switch between them through the orchard dashboard? That is, in stead of default you might have SiteOne, SiteTwo, and toggle between them if you wish?

I was merely curious if this were a possibility.

Yep. Just enable the multi-tenancy module.