I've just found this site and it's packed full of such useful information.
We are planning our 2010 flydrive holiday and having explored the west coast a few years ago we want to explore the east next year.
We were thinking of taking 3 weeks to drive from Boston to Washington DC taking in New York, Gettysburg and Amish country, Philadelphia, Charlottesville and Williamsburg on the way. We fancied Niagara Falls too but don't see how that could be included as it seems quite a detour.
We don't want to spend all our time on the interstate and are hoping for some suggestions for other must see places to see inbetween.