3,000 Mile Bike Trail to allow you to bike from Maine to Florida
Sounds sweet, not sure if its going to be going through great scenic areas always or not, but its already 850 miles long with the plan to get to 3000 miles long.
It's called the Greenway Bike Trail and you can explore the current trail and plan a trip on it here: http://www.greenway.org/explore
I plan on checking this out soon