Originally Posted by
Pureboy
I don't know about non-shinkansen transportation, but consider a half-day trip to Himeji. Arguably the best castle in Japan, and newly restored.
+1 for Himeji. Also easily accessible via Shinkansen (it's just down the street from the train station).
You don't need reservations for the standard rail pass but you can easily make reservations at the ticket window if you want.