The New York Times's Frugal Traveler managed to avoid renting a car to drive up to far northern Honshu for a hike around the famous hot springs there -- then spent $100 a night at the ryokan for his bed and meals. I'd love to do this some day.
"The Avis WIZARD decides if you get to drive a car. Your head won't touch the pillow of a Sheraton unless their computer says it's okay." -- Arthur Miller